Firefox Changelog

What's new in Firefox 125.0.1

Apr 17, 2024

New:
Firefox now supports the AV1 codec for Encrypted Media Extensions (EME), enabling higher-quality playback from video streaming providers.
The Firefox PDF viewer now supports text highlighting.
Firefox View now displays pinned tabs in the Open tabs section. Tab indicators have also been added to Open tabs, so users can do things like see which tabs are playing media and quickly mute or unmute across windows. Indicators were also added for bookmarks, tabs with notifications, and more!
Firefox now prompts users in the US and Canada to save their addresses upon submitting an address form, allowing Firefox to autofill stored address information in the future.
Firefox now more proactively blocks downloads from URLs that are considered to be potentially untrustworthy.
The URL Paste Suggestion feature provides a convenient way for users to quickly visit URLs copied to the clipboard in the address bar of Firefox. When the clipboard contains a URL and the URL bar is focused, an autocomplete result appears automatically. Activating the clipboard suggestion will navigate the user to the URL with 1 click.
Users of tab-specific Container add-ons can now search in the Address Bar for tabs that are open in different containers. Special thanks to volunteer contributor atararx for kicking off the work on this feature!
Firefox now provides an option to enable Web Proxy Auto-Discovery (WPAD) while configured to use system proxy settings.
Fixed:
Various security fixes.
Changed:
In a group of radio buttons where no option is selected, the tab key now only reaches the first option rather than cycling through all available options. The arrow keys navigate between options as they do when there is a selected option. This makes keyboard navigation more efficient and consistent.
Developer:
Following several requests, we have reintroduced the option to disable the Pause Debugger Overlay (devtools.debugger.features.overlay). This overlay appears over the page content when the debugger pauses JavaScript execution. In certain scenarios, the overlay can be intrusive, making it challenging to interact with the page, for instance, evaluating shades of color underneath.
We've added a new drop-down menu button at the bottom of the source view in the Debugger panel, specifically designed for Source Map related actions. Users can now easily disable or enable Source Maps support, open the Source Map file in a new tab, switch between the original source and the generated bundle, toggle the "open original source by default" option, and view the Source Map status such as errors, loading status, etc.
Web Platform:
Firefox now supports the popover global attribute used for designating an element as a popover element. The element won't be rendered until it is made visible, after which it will appear on top of other page content.
WebAssembly multi-memory is now enabled by default. Wasm multi-memory allows wasm modules to use and import multiple independent linear memories. This enables more efficient interoperability between modules and provides better polyfills for upcoming wasm standards, such as the component model.
Added support for Unicode Text Segmentation to JavaScript.
Added support for contextlost and contextrestored events on HTMLCanvasElement and OffscreenCanvas to allow user code to recover from context loss with hardware accelerated 2d canvas.
Firefox now supports the navigator.clipboard.readText() web API. A paste context menu will appear for the user to confirm when attempting to read clipboard data not provided by the same-origin page.
Added support for the content-box and stroke-box keywords of the transform-box CSS property.
The align-content property now works in block layout, allowing block direction alignment without needing a flex or grid container.
Support for SVGAElement.text was removed in favor of the more widely-implemented SVGAElement.textContent method.

New in Firefox 124.0.2 (Apr 2, 2024)

New in Firefox 124.0.1 (Mar 22, 2024)

New in Firefox 124.0 (Mar 19, 2024)

New in Firefox 123.0.1 (Mar 5, 2024)

New in Firefox 123.0 (Feb 20, 2024)

New:
We’ve integrated search into Firefox View. You can now search through all of the tabs on each of the section subpages - Recent Browsing, Open Tabs, Recently Closed Tabs, Tabs from other devices, or History.
Having any issues with a website on Firefox, yet the site seems to be working as expected on another browser? You can now let us know via the Web Compatibility Reporting Tool! By filing a web compatibility issue, you’re directly helping us detect, target, and fix the most impacted sites to make your browsing experience on Firefox smoother.
Fixed:
When translating web pages, we are now also translating text in tooltips (i.e. titles) and text displayed in form controls (i.e. placeholder).
Various security fixes.
Changed:
Address bar settings can now be found in the Firefox Settings' Search section.
Improved PGO optimizations for macOS ARM64 and Android
Off-main-thread canvas on macOS, Linux and Android
Developer:
The Network Monitor now supports saving a response body to disk through the Save Response As context menu item. This replaces the Save Image context menu item, which only supported saving images.
Web Platform:
We now implement linearRGB interpolation for SVG gradients, as well as the existing sRGB interpolation. You can choose which to use via the color-interpolation property.
Previously, SVG feImage elements that pointed to SVG content required the SVG document to have a root element that had non-percentage width and height values. Such content will now fall back to use the default replaced element values of 300px width and 150px height and the feImage will no longer fail to render.
By enabling Preload and Modulepreload support, Early Hints are now fully supported.
Audio echo cancellation can now be applied to microphone inputs when the audio output is redirected to another device with setSinkId().
Firefox now supports declarative ShadowDOM, providing developers greater flexibility and improved ergonomics when working with ShadowDOMs directly within HTML.
Unresolved:
Some machines with older AMD CPUs may see image thumbnails incorrectly render as all black in file dialogs. If this is the case, updating the graphics driver should address this issue.

New in Firefox 122.0.1 (Feb 7, 2024)

New in Firefox 122.0 (Jan 23, 2024)

New:
Firefox now displays images and descriptions for search suggestions when provided by the search engine.
The translations feature received an improvement in the quality of translated webpages. The results should be much more stable. This fixes issues where the content of a page could disappear when translated, or interactive widgets could break.
Firefox now supports creating and using passkeys stored in the iCloud Keychain on macOS.
MDN Web Docs article suggestions from Firefox Suggest will be available in the address bar for users searching for web development-related information.
The line breaking rules of Web content now match the Unicode Standard. This improves Web Browser compatibility for line breaking. An additional improvement for East Asian and South East Asian end users, Firefox now supports proper language-aware word selection when double-clicking on text for languages including Chinese, Japanese, Burmese, Lao, Khmer, and Thai.
Firefox now ships with a new .deb package for Linux users on Ubuntu, Debian, and Linux Mint.
Fixed:
Various security fixes.
Developer:
Fixing keyboard navigation in Inspector Rules view. Starting with Firefox 122, when editing a selector, a property name, or a property value in the Inspector, the Enter key will no longer move the focus to the next input but will validate what was entered and focus the matching element (#1861674). You can still use Ctrl + Enter (Cmd + Enter on macOS) or Tab to validate and move the focus to the next input.
Web Platform:
Enabled the offset-position property which is useful for most of the offset-path values. Added support for ray(), basic-shape, coord-box to the offset-path CSS property. Added support for rect() and xywh() basic shapes on clip-path and offset-path CSS properties.
Firefox now supports animating the SVG viewBox attribute using SMIL by animations.
by animations are animations that are relative to the original value. Other attributes such as lengths and angles already support by, but a viewBox consists of four separate values.
The LargestContentfulPaint API has been added, this provides timing information about the largest image or text paint before users interact with a web page.
hr in select is now supported, allowing websites to easily use separators inside a select element.
The showPicker method is now supported on elements, this can be used to trigger the drop-down behavior via JavaScript.
The fallback URL parser for unknown schemes was changed to DefaultURI, this improves specification adherence and web compatibility.
Enabled the ArrayBuffer.prototype.transfer proposal methods, which enables transferring ownership of ArrayBuffer data.
Added support for the Screen Wake Lock API.
Firefox now recognizes the “webauthn” autocomplete token and will suggest passkeys in form autofill dialogs.
Scripts can now store cacheAPI data in Private Browsing mode. Previously, user experience for someone browsing in private browsing mode could be significantly different than in regular mode. With these changes, websites can store cacheAPI data in Private Mode moving towards a uniform experience in regular vs Private Browsing mode.
To further protect user privacy, Firefox now taints filters that use currentColor as an input. Since color can be set by the :visited pseudo selector, it potentially contains privacy-sensitive information and therefore these primitives must be marked as tainted. This means that if you use such a filter, you won’t be able to read the filter output from canvas.
Uneven Level Protection Forward Error Correction (ULPFEC) will now be on by default in Firefox. This provides another tool for WebRTC services to utilize, improving video quality for users with spotty internet connections.
Unresolved:
Some machines with older AMD CPUs may see image thumbnails incorrectly rendered as all black in file dialogs. If this is the case, updating the graphics driver should address this issue.

New in Firefox 121.0.1 (Jan 9, 2024)

New in Firefox 121.0 (Dec 19, 2023)

New:
Firefox now prompts Windows users to install the Microsoft AV1 Video Extension to enable hardware decoding support for the AV1 video codec from about:support if not already installed.
Firefox now supports Voice Control commands on macOS systems.
On Linux, Firefox now defaults to the Wayland compositor when available instead of XWayland. This brings support for touchpad & touchscreen gestures, swipe-to-nav, per-monitor DPI settings, better graphics performance, and more.
Note that due to Wayland protocol limitations, Picture-in-Picture windows require an extra user interaction (generally right-click on the window) or a shell / desktop-environment tweak. See bug 1621261 for related discussion and tracking, this post for a KDE configuration, and this extension for GNOME.
Firefox can now force links to always be underlined. This option can be enabled in the Browsing section of the Firefox Settings menu.
The PDF viewer now includes a floating button to simplify deleting drawings, text, and images added in PDFs.
Fixed:
Various security fixes.
Developer:
Developer Information:
The Firefox Debugger now includes a new feature: an option to disable the debugger; keyword on the current page. This feature is accessible via a new checkbox in the Breakpoints side panel labeled Pause on debugger statement, located next to the existing Pause on exceptions checkbox. By default, this option is enabled, meaning that the debugger statements are active unless manually disabled.
As part of our work on improving the accessibility of Firefox Developer Tools, we've unified the focus indicator across the toolbox. The focus indicator is now larger with improved contrast, featuring a white box-shadow for enhanced visibility on blue backgrounds. Adjustments have also been made to ensure clear visibility across shared components and frequently used panels, preventing overlap with element borders or backgrounds.
Web Platform:
The :has() selector is now supported. This allows authors to match an element that has, or "anchors", at least one element matching its relative selector.
The hanging and each-line keywords are now supported for the text-indent CSS property, offering more convenient paragraph layout options for styles such as bibliographies, poetry, etc.
The balance keyword is now supported for the text-wrap CSS property, which can improve the appearance of short multi-line text blocks such as long headings or captions by harmonizing the line lengths.
Lazy loading iframes are now supported (). Lazy loading iframes are only loaded when visible, so non-critical iframes can load later when needed to speed up initial page loads, reduce initial network usage, etc.
Support has been added for tail call elimination in WebAssembly language to improve support for functional languages.

New in Firefox 120.0.1 (Dec 2, 2023)

New in Firefox 120.0 (Nov 21, 2023)

New:
Firefox supports a new “Copy Link Without Site Tracking” feature in the context menu which ensures that copied links no longer contain tracking information.
Firefox now supports a setting (in Preferences → Privacy & Security) to enable Global Privacy Control. With this opt-in feature, Firefox informs the websites that the user doesn’t want their data to be shared or sold.
Firefox’s private windows and ETP-Strict privacy configuration now enhance the Canvas APIs with Fingerprinting Protection, thereby continuing to protect our users’ online privacy.
Firefox has enabled Cookie Banner Blocker by default in private windows for all users in Germany. Firefox will now auto-refuse cookies and dismiss annoying cookie banners for supported sites.
Firefox has enabled URL Tracking Protection by default in private windows for all users in Germany. Firefox will remove non-essential URL query parameters that are often used to track users across the web.
Firefox now imports TLS trust anchors (e.g., certificates) from the operating system root store. This will be enabled by default on Windows, macOS, and Android, and if needed, can be turned off in settings (Preferences → Privacy & Security → Certificates).
Keyboard shortcuts have now been added for editing and deleting a selected credential on about:logins. For editing - Alt + enter (Option + return on macOS) and for deleting - Alt + Backspace (Option + Delete on macOS).
Users on Ubuntu Linux now have the ability to import from Chromium when both are installed as Snap packages.
Picture-in-Picture now supports corner snapping on Windows and Linux - just hold Ctrl as you move the PiP window.
Fixed:
Various security fixes.
Developer:
The User Activation API has now been added, allowing JavaScript to check if the user currently is or has been active with the page (clicking, etc) with navigator.userActivation.
Early Hints Preconnect, the informational status code 103, is now enabled. This allows servers to send resource Link headers before the final HTTP response and improves performance on servers using this feature. (read more)
Users can now use an added devtools feature to simulate browser tabs to be offline.
The Style Editor panel now features a new "Pretty Print" button located in the footer of the panel, similar to the pretty print button found in the Debugger panel. This can be used to format stylesheets (e.g., those that are minified). The previous functionality, where minified files were automatically formatted, has been removed.
The Rules panel within the Inspector panel now displays colors in the new CSS Color 4 formats (e.g., OKLCH) as hexadecimal/named colors. This ensures that it matches the original values used by the current page.
Web Platform:
lh and rlh units can now be parsed and computed correctly as lengths. This allows authors to specify lengths in terms of the element's (or the root element's) line height.
WebAssembly GC is now enabled by default, which allows new languages, such as Dart or Kotlin, to run on Firefox. This makes it possible for reference cycles between the guest language and host browser to be collected.

New in Firefox 119.0.1 (Nov 7, 2023)

New in Firefox 119.0 (Oct 24, 2023)

New:
Gradually rolling out in Fx119, Firefox View includes more content. You can now see all open tabs, from all windows. If you sync open tabs, you’ll see all tabs from other devices. Browsing history is now listed and you can sort by date or by site. As before, recently closed tabs are also listed on Firefox View.
To access Firefox View, select the file folder icon at the top left of your tab strip.
Gradually rolling out in Fx119, Firefox now allows you to edit PDFs by adding images and alt text, in addition to text and drawings.
Recently closed tabs now persist between sessions that don't have automatic session restore enabled. Manually restoring a previous session will continue to reopen any previously open tabs or windows.
If you're migrating your data from Chrome, Firefox now offers the ability to import some of your extensions as well.
As part of Total Cookie Protection, Firefox now supports the partitioning of Blob URLs, this mitigates a potential tracking vector that third-party agents could use to track an individual.
The visibility of fonts to websites has been restricted to system fonts and language pack fonts in Enhanced Tracking Protection strict mode to mitigate font fingerprinting.
The Storage Access API web standard was updated to improve security while mitigating website breakages and further enabling the phase out of third-party cookies in Firefox.
Encrypted Client Hello (ECH) is now available to Firefox users, delivering a more private browsing experience. ECH extends the encryption used in TLS connections to cover more of the handshake and better protect sensitive fields. Read more about the launch of ECH on Mozilla Distilled.
Media sniffing is no longer applied to files served as type application/octet-stream, this allows these files to be downloaded instead of attempting playback.
On Windows, the mouse pointer will disappear while typing if the relevant Windows mouse properties system setting is enabled.
Firefox is now available in the Santali (sat) language.
Fixed:
Fixed an issue causing unexpected jumps in scroll position on Facebook.
Various security fixes.
Developer:
Several enhancements have been made to the Inactive CSS styles feature. This feature assists in identifying CSS properties that have no effect on an element. Pseudo-elements such as ::first-letter, ::cue, and ::placeholder are now fully supported.
The JSON viewer is particularly useful for debugging REST APIs, as it displays formatted JSON responses. Now, if the JSON is invalid or broken, it automatically switches to a raw data view, improving the user experience.
Web Platform:
ARIA reflection for simple attributes and default Accessibility Semantics for Custom Elements are now supported. Note this includes boolean, enum, number, and string attributes, but not attributes that reference other elements.
credentialless is now supported in Cross-Origin-Embedder-Policy.
The CSS attr() function now supports a fallback parameter, for example attr(foobar, "Default value").
Grouping of items in an array (and iterables) is now easier by using the methods Object.groupBy or Map.groupBy.

New in Firefox 118.0.2 (Oct 10, 2023)

New in Firefox 118.0.1 (Sep 28, 2023)

New in Firefox 118.0 (Sep 26, 2023)

New in Firefox 117.0.1 (Sep 12, 2023)

New in Firefox 117.0 (Aug 29, 2023)

New in Firefox 116.0.3 (Aug 16, 2023)

New in Firefox 116.0.2 (Aug 7, 2023)

New in Firefox 116.0.1 (Aug 4, 2023)

New in Firefox 116.0 (Aug 2, 2023)

New:
Sidebar switcher allows users to access Bookmarks, History and Synced Tabs panels easily, quickly switch between them, move the sidebar to another side of the browser window, or close the sidebar. Now, keyboard users would be able to do it all with ease too, with or without any assistive technology running, without needing to memorize keyboard shortcuts to access these panels.
When an update is available in English locales, users will now have access to the release notes in the update notification prompt in the form of a "Learn More" link.
It is now possible to copy any file from your operating system and paste it into Firefox.
You asked, and we listened! The volume slider is now available in Picture-in-Picture.
We added the possibility to edit existing text annotations.
Fixed:
The upload performance of HTTP/2 has been significantly improved starting with Firefox 115.0, particularly on those with a higher bandwidth delay product (i.e., networks characterized by both high bandwidth and high latency).
Various security fixes.
Changed:
The keyboard shortcut to reopen closed tabs (command + shift + t) now reopens last closed tab or last closed window, in the order items were closed. If there aren't any tabs or windows to reopen, this command restores the previous session. This change is in anticipation of upcoming changes to recently closed tabs.
Developer:
Added support for the dirname attribute to pass text directionality information about input and textarea elements to the server. (learn more)
Firefox now supports CSP3 external hashes.
The Audio Output Devices API now enables sites to redirect audio from media elements to permitted output devices (speakers) other than the system default for the user-agent.
For example, WebRTC conferencing sites can now redirect audio either to the speakers in a headset or to external speakers.
With custom formatters, websites can now define how to display specific JavaScript objects and functions within different parts of the DevTools. This feature is disabled by default and can be enabled via the Settings panel. (Learn more)
Web Platform:
This release now supports proper BYOB readers on Fetch and WebTransport, which allows developers to prepare their ArrayBuffer so that it can be reused for read requests and thus saves memory allocation. .getReader({ mode: "byob" }) on Fetch and WebTransport streams was supported on previous releases but without true BYOB support, as new memory allocation still occurred internally.

New in Firefox 115.0.3 (Jul 27, 2023)

New in Firefox 115.0.2 (Jul 11, 2023)

New in Firefox 115.0.1 (Jul 7, 2023)

New in Firefox 115.0 (Jul 6, 2023)

New:
Migrating from another browser? Now you can bring over payment methods you've saved in Chrome-based browsers to Firefox.
Hardware video decoding is now enabled for Intel GPUs on Linux.
The Tab Manager dropdown now features close buttons, so you can close tabs more quickly.
We've refreshed and streamlined the user interface for importing data in from other browsers.
Users without platform support for H264 video decoding can now fallback to Cisco's OpenH264 plugin for playback.
Fixed:
Windows Magnifier now follows the text cursor correctly when the Firefox title bar is visible.
Windows users on low-end/USB wifi drivers and with OS geolocation disabled can now approve geolocation on a case by case basis without causing system-wide network instability.
Various security fixes.
Changed:
Undo and redo are now available in Password fields.
On Linux, middle clicks on the new tab button will now open the xclipboard contents in the new tab. If the xclipboard content is a URL then that URL is opened, any other text is opened with your default search provider.
For users with a Firefox Colorways built-in theme, the theme will be automatically migrated to the same theme hosted on addons.mozilla.org for Firefox profiles that have disabled add-ons auto-updates. This will allow users to keep their Colorways theme when they are later removed from Firefox installer files.
Certain Firefox users may come across a message in the extensions panel indicating that their add-ons are not allowed on the site currently open. We have introduced a new back-end feature to only allow some extensions monitored by Mozilla to run on specific websites for various reasons, including security concerns.
Developer:
In web development, we rely on third-party libraries which you may not be interested in while debugging. These can be ignored. Ignoring them means that breakpoints will not get hit and they are skipped during stepping.
You can now choose to Hide ignore-listed sources in the Developer Tools source tree (bug).
Ignored sources are also skipped by JavaScript tracing feature (bug).
We have introduced a new option, devtools.f12_enabled, that can be utilized to prevent the accidental use of the F12 key, which opens the DevTools toolbox (bug).
Web Platform:
The builtin editor now behaves similarly to other browsers with contenteditable and designMode when splitting a node, e.g. typing Enter to split a paragraph, and also when joining two nodes, e.g. typing Backspace at the start of a paragraph to join the paragraph and the previous one.
When a node is split, the builtin editor creates a new node after the original one instead of before, i.e. creates the right node instead of the left node.
Similarly, when two nodes are joined, the builtin editor deletes the latter node and moves its children to the end of the preceding node instead of deleting the former node and moving its child to the start of the following node.
WebRTC application developers can now specify a target in milliseconds of media for the jitter buffer to hold. Altering the target value allows applications to control the tradeoff between playout delay and the risk of running out of audio or video frames due to network jitter.
Change array by copy provides additional methods on Array.prototype and TypedArray.prototype to enable changes on the array by returning a new copy of it with the change.
The animation-composition property is now supported, allowing a declarative way to define the composite operation used when multiple animations affect the same property simultaneously.
Added the URL.canParse() function to allow easy and fast checking if URLs are valid and parseable.
IndexedDB is now also supported in private browsing without memory limits thanks to encrypted storage on disk. The temporary keys to decrypt the information are held in RAM only and all stored information is purged at the normal end of a private browsing session from disk.
Supports conditions are now supported in CSS import rules @import supports(...)

New in Firefox 114.0.2 (Jun 20, 2023)

New in Firefox 114.0.1 (Jun 9, 2023)

New in Firefox 114.0 (Jun 6, 2023)

New:
Added UI to manage the DNS over HTTPS exception list.
Bookmarks can now be searched from the Bookmarks menu. The Bookmarks menu is accessible by adding the Bookmarks menu button to the toolbar.
Restrict searches to your local browsing history by selecting Search history from the History, Library or Application menu buttons.
Mac users can now capture video from their cameras in all supported native resolutions. This enables resolutions higher than 1280x720.
It is now possible to reorder the extensions listed in the extensions panel.
Users on macOS, Linux, and Windows 7 can now use FIDO2 / WebAuthn authenticators over USB. Some advanced features, such as fully passwordless logins, require a PIN to be set on the authenticator.
Pocket Recommended content can now be seen in France, Italy, and Spain.
Fixed:
Various security fixes.
Changed:
DNS over HTTPS settings are now part of the Privacy & Security section of the Settings page and allow the user to choose from all the supported modes.
Developer:
The Copy as cURL feature, available in the Network panel, has been enhanced. It now supports the --compressed argument.
The Accessibility Inspector has been improved to accurately recognize all the ARIA roles like banner, main, navigation, and contentinfo, etc. This enhancement is particularly beneficial for web developers working with ARIA roles to improve web accessibility.
Firefox now provides support for the CSS Cascading Level 4 supports() syntax for @import rules. This allows for the importation of other stylesheets based on support-dependency. In addition, the Inspector panel now accurately displays the conditions at the top of the imported rule.
Web Platform:
DOM: Added support for ES Modules on DedicatedWorker and SharedWorker
WebTransport is now enabled by default and will be going to release with 114. As the original Explainer notes, it enables multiple use-cases that are hard or impossible to handle without it, especially for Gaming and live streaming. It covers cases that are problematic for alternative mechanisms, such as WebSockets.
Built on top of HTTP3 (HTTP2 support will be coming later). The current implementation in Firefox is passing 505 out of 565 Web-Platform Tests.
CSS: The infinity and NaN constants are now supported inside the calc() function.

New in Firefox 113.0.2 (May 23, 2023)

New in Firefox 113.0.1 (May 12, 2023)

New in Firefox 113.0 (May 9, 2023)

New:
Say hello to enhanced Picture-in-Picture! Rewind, check video duration, and effortlessly switch to full-screen mode on the web's most popular video websites.
Firefox's address bar is already a great place to search for what you're looking for. Now you'll always be able to see your web search terms and refine them while viewing your search's results - no additional scrolling needed! Also, a new result menu has been added making it easier to remove history results and dismiss sponsored Firefox Suggest entries.
Image demonstrating search terms persisting in the address bar after hitting Enter for easier editing
Private windows now protect users even better by blocking third-party cookies and storage of content trackers.
Passwords automatically generated by Firefox now include special characters, giving users more secure passwords by default.
Importing bookmarks from Safari or a Chrome-based browser? The favicons for those bookmarks will now also be imported by default to make them easier to identify.
Firefox 113 now supports AV1 Image Format files containing animations (AVIS), improving support for AVIF images across the web.
The Windows GPU sandbox first shipped in the Firefox 110 release has been tightened to enhance the security benefits it provides.
A 13-year-old feature request was fulfilled and Firefox now supports files being drag-and-dropped directly from Microsoft Outlook. A special thanks to volunteer contributor Marco Spiess for helping to get this across the finish line!
Users on macOS can now access the Services sub-menu directly from Firefox context menus.
On Windows, the elastic overscroll effect has been enabled by default. When two-finger scrolling on the touchpad or scrolling on the touchscreen, you will now see a bouncing animation when scrolling past the edge of a scroll container.
Firefox is now available in the Tajik (tg) language.
Firefox 113 introduces a redesigned accessibility engine which significantly improves the speed, responsiveness, and stability of Firefox when used with:
Screen readers, as well as certain other accessibility software;
East Asian input methods;
Enterprise single sign-on software; and
Other applications which use accessibility frameworks to access information.
Fixed:
Various security fixes.
Changed:
The long-deprecated mozRTCPeerConnection, mozRTCIceCandidate, and mozRTCSessionDescription WebRTC interfaces have been removed. Sites should utilize the non-prefixed versions instead.
Developer:
Developer Information:
There have been numerous improvements to the Debugger's "Search in files" feature (also known as "Project search"):
The panel has been moved to a regular side panel, which allows you to keep the results list visible while opening scripts in the editor;
Results from minified and pretty-printed tabs, as well as matches from the node_modules folder, are displayed;
Results from ignored files are hidden; and
Glob patterns and search modifiers are also supported, making it possible to execute case-sensitive or regex searches on specific parts of your project.
Additional features include support for pretty printing inline scripts in HTML files and column breakpoints in pretty printed sources.
It is now possible to override a JavaScript file in the debugger. In the Debugger, under the Sources tree, you can use the "Add script override" context menu entry. This action will download the file onto your machine, allowing you to edit it. After reloading the page, the local file will be loaded instead of the original script (indicated by a purple icon when a file is overridden).

New in Firefox 112.0.2 (Apr 25, 2023)

New in Firefox 112.0.1 (Apr 25, 2023)

New in Firefox 112.0 (Apr 11, 2023)

New in Firefox 111.0.1 (Mar 22, 2023)

New in Firefox 111.0 (Mar 14, 2023)

New in Firefox 110.0.1 (Mar 1, 2023)

New in Firefox 110.0 (Feb 15, 2023)

New:
It's now possible to import bookmarks, history and passwords not only from Edge, Chrome or Safari but also from Opera, Opera GX, and Vivaldi for all the folks who want to move over to Firefox instead!
GPU sandboxing has been enabled on Windows.
Note: A bug in the popular X-Mouse Button Control (XMBC) tool may cause mouse wheel scrolling to stop working. The author(s) are working on an update. Meanwhile, scrolling can be restored by reconfiguring XMBC: either disable the Make scroll wheel scroll window under cursor option in the global settings, or enable the Disable scroll window under cursor option if using a custom profile for Firefox.
On Windows, third-party modules can now be blocked from injecting themselves into Firefox, which can be helpful if they are causing crashes or other undesirable behavior.
Date, time, and datetime-local input fields can now be cleared with Cmd+Backspace and Cmd+Delete shortcut on macOS and Ctrl+Backspace and Ctrl+Delete on Windows and Linux.
GPU-accelerated Canvas2D is enabled by default on macOS and Linux.
WebGL performance improvement on Windows, MacOS and Linux.
Enables overlay of hardware-decoded video with non-Intel GPUs on Windows 10/11, improving video playback performance and video scaling quality.
Fixed:
Various security fixes.
Changed:
Colorways are no longer available in Firefox, at least not in the same way. You can still access your saved and active Colorways by selecting Add-ons and themes from the Firefox menu. Additionally, you can now install Colorways from all of the previous collections by visiting Colorways by Firefox on the Mozilla Add-ons website.
Enterprise:
Various bug fixes and new policies have been implemented in the latest version of Firefox. You can find more information in the Firefox for Enterprise 110 Release Notes.
Web Platform:
Firefox now supports CSS named pages, allowing web pages to perform per-page layout and add page-breaks in a declarative manner when printing.
Firefox now supports CSS size container queries, see the MDN page for documentation on this feature.

New in Firefox 109.0.1 (Jan 30, 2023)

New in Firefox 109.0 (Jan 17, 2023)

New:
Manifest Version 3 (MV3) extension support is now enabled by default (MV2 remains enabled/supported). This major update also ushers an exciting user interface change in the form of the new extensions button.
The Arbitrary Code Guard exploit protection has been enabled in the media playback utility processes, improving security for Windows users.
The native HTML date picker for date and datetime inputs can now be used with a keyboard alone, improving its accessibility for screen reader users. Users with limited mobility can also now use common keyboard shortcuts to navigate the calendar grid and month selection spinners.
Firefox builds in the Spanish from Spain (es-ES) and Spanish from Argentina (es-AR) locales now come with a built-in dictionary for the Firefox spellchecker.
Fixed:
Various security fixes.
Changed:
Effective on January 16, Colorways will no longer be in Firefox. Users will still be able to access saved and active Colorways from the Add-ons and themes menu option.
On macOS, Ctrl or Cmd + trackpad or mouse wheel now scrolls the page instead of zooming. This avoids accidental zooming and matches the behavior of other web browsers on macOS.
The Recently Closed section of Firefox View now equips users with the ability to manually close/remove url links from the list.
The empty state messages and graphic components surfaced in Firefox View for the Tab Pickup and Recently Closed sections have been updated for an improved user experience.
Developer:
The ability to automatically break when code on the page hits an events handler has been available since Firefox 69. Firefox 109 now adds new support for the scrollend event. To use this new event breakpoint, open the JS debugger and find and expand the Event Listener Breakpoints section in the right hand column (learn more).
Screenshot of Breakpoint options showing new scrollend event availability
Web Platform:
The scrollend event is now enabled by default. The event is fired when a scroll has completed.
Firefox now permanently partitions Storage in third-party contexts independent of Storage Access to align with other browsers and provide better Web compatibility.

New in Firefox 108.0.2 (Jan 5, 2023)

New in Firefox 108.0.1 (Dec 16, 2022)

New in Firefox 108.0 (Dec 13, 2022)

New in Firefox 107.0.1 (Dec 13, 2022)

New in Firefox 107.0 (Nov 15, 2022)

New in Firefox 106.0.5 (Nov 6, 2022)

New in Firefox 106.0.4 (Nov 4, 2022)

New in Firefox 106.0.3 (Oct 31, 2022)

New in Firefox 106.0.2 (Oct 27, 2022)

New in Firefox 106.0.1 (Oct 20, 2022)

New in Firefox 106.0 (Oct 18, 2022)

New:
It is now possible to edit PDFs: including writing text, drawing, and adding signatures.
Setting Firefox as your default browser now also makes it the default PDF application on Windows systems.
You can now pin private windows to your Windows taskbar on Window 10 and Windows 11 for simpler access. Also, private windows have been redesigned to increase the feeling of privacy.
Swipe-to-navigate (two fingers on a touchpad swiped left or right to perform history back or forward) now works for Linux users on Wayland.
Text Recognition in images allows users on macOS 10.15 and higher to extract text from the selected image (such as a meme or screenshot).
Extracted text is copied to the clipboard in order to share, store, or search—without needing to manually retype everything:
This feature is compatible with “VoiceOver,” the built-in macOS screen reader.
For more information, check out our SUMO article.
New
It is now possible to edit PDFs: including writing text, drawing, and adding signatures.
Setting Firefox as your default browser now also makes it the default PDF application on Windows systems.
You can now pin private windows to your Windows taskbar on Window 10 and Windows 11 for simpler access. Also, private windows have been redesigned to increase the feeling of privacy.
Private browsing screenshot
Swipe-to-navigate (two fingers on a touchpad swiped left or right to perform history back or forward) now works for Linux users on Wayland.
Text Recognition in images allows users on macOS 10.15 and higher to extract text from the selected image (such as a meme or screenshot).
Extracted text is copied to the clipboard in order to share, store, or search—without needing to manually retype everything.
This feature is compatible with “VoiceOver,” the built-in macOS screen reader.
“Firefox View” helps you get back to content you previously discovered. A pinned tab allows you to find and open recently closed tabs on your current device, access tabs from other devices (via our “Tab Pickup” feature), and change the look of the browser (with Colorways).
With the launch of the “Independent Voices” collection, Firefox is introducing 18 new “Colorways.” You can now access a “Colorways” modal experience via “Firefox View”; each new color is accompanied with a bespoke graphic and a text description that speaks to its deeper meaning. The collection will be available through Jan 16.
Fixed:
Various security fixes.

New in Firefox 105.0.3 (Oct 10, 2022)

New in Firefox 105.0.2 (Oct 7, 2022)

New in Firefox 105.0.1 (Sep 23, 2022)

New in Firefox 105.0 (Sep 20, 2022)

New in Firefox 104.0.2 (Sep 6, 2022)

New in Firefox 104.0.1 (Aug 30, 2022)

New in Firefox 104.0 (Aug 23, 2022)

New in Firefox 103.0.2 (Aug 9, 2022)

New in Firefox 103.0.1 (Aug 1, 2022)

New in Firefox 103.0 (Jul 26, 2022)

New in Firefox 102.0.1 (Jul 6, 2022)

New in Firefox 102.0 (Jun 28, 2022)

New in Firefox 101.0.1 (Jun 11, 2022)

New in Firefox 101.0 (May 31, 2022)

New:
Reading is now easier with the prefers-contrast media query, which allows sites to detect if the user has requested that web content is presented with a higher (or lower) contrast.
It’s your choice! All non-configured MIME types can now be assigned a custom action upon download completion.
Firefox now allows users to use as many microphones as you want, at the same time, during video conferencing. The most exciting benefit is that you can easily switch your microphones at any time (if your conferencing service provider enables this flexibility).
Fixed:
Various security fixes.
Developer:
Inspector panel: When adding/removing a class name to/from an existing HTML element (using .cls button in Rules View), an autocomplete drop down automatically offers all existing class names on the page. In Firefox 101 the selected class name in the autocomplete drop-down list is auto-applied immediately as the user changes the selection of the autocomplete list (using up/down arrow keys). This is especially useful for quick testing of various styles.
Inspector panel: This new option can be used to disable “drag to update” features in the Rule View (values of some CSS properties e.g., sizes can be modified by dragging the mouse horizontally).
WebDriver BiDi: This protocol is enabled on the release channel to support external tools such as Selenium, which plan to start using WebDriver BiDi for Firefox. WebDriver-BiDi aims to provide a cross-browser protocol for browser automation that meets the requirements of modern web application testing tools. This allows both the client and the server to send & receive requests and responses.
Web Platform:
Firefox new has added support for large, small, dynamic viewport units and logical ones (*vi and *vb). This gives users the flexibility to choose whether page elements are sized to the “smallest” viewport size (dynamic toolbar visible), “largest” viewport size (dynamic toolbar hidden), or “dynamic” viewport size (based on current status of dynamic toolbar).
Firefox 101 features added web conferencing support for enumerating (reducing errors caused by transposing or mistyping numbers) and selecting multiple audio input devices (giving you the ability to record or process multiple separate audio sources together, synchronously, at once) through navigator.mediaDevices.enumerateDevices().

New in Firefox 100.0.2 (May 23, 2022)

New in Firefox 100.0.1 (May 16, 2022)

New in Firefox 100.0 (May 3, 2022)

New:
We now support captions/subtitles display on YouTube, Prime Video, and Netflix videos you watch in Picture-in-Picture. Just turn on the subtitles on the in-page video player, and they will appear in PiP.
Picture-in-Picture now also supports video captions on websites that use WebVTT (Web Video Text Track) format, like Coursera.org, Canadian Broadcasting Corporation, and many more.
On the first run after install, Firefox detects when its language does not match the operating system language and offers the user a choice between the two languages.
Firefox spell checking now checks spelling in multiple languages. To enable additional languages, select them in the text field’s context menu.
HDR video is now supported in Firefox on Mac—starting with YouTube! Firefox users on macOS 11+ (with HDR-compatible screens) can enjoy higher-fidelity video content. No need to manually flip any preferences to turn HDR video support on—just make sure battery preferences are NOT set to “optimize video streaming while on battery”.
Hardware accelerated AV1 video decoding is enabled on Windows with supported GPUs (Intel Gen 11+, AMD RDNA 2 Excluding Navi 24, GeForce 30). Installing the AV1 Video Extension from the Microsoft Store may also be required.
Video overlay is enabled on Windows for Intel GPUs, reducing power usage during video playback.
Improved fairness between painting and handling other events. This noticeably improves the performance of the volume slider on Twitch.
Scrollbars on Linux and Windows 11 won't take space by default. On Linux, users can change this in Settings. On Windows, Firefox follows the system setting (System Settings > Accessibility > Visual Effects > Always show scrollbars).
Firefox now supports credit card autofill and capture in the United Kingdom.
Firefox now ignores less restricted referrer policies—including unsafe-url, no-referrer-when-downgrade, and origin-when-cross-origin—for cross-site subresource/iframe requests to prevent privacy leaks from the referrer.
Fixed:
Users can now choose preferred color schemes for websites. Theme authors can now make better decisions about which color scheme Firefox uses for menus. Web content appearance can now be changed in Settings.
Beginning in this release, the Firefox installer for Windows is signed with a SHA-256 digest, rather than SHA-1. Update KB4474419 is required for successful installation on a computer running Microsoft Windows 7. For more details about this update, visit the Microsoft Technical Support website.
In macOS 11+ we now only rasterize the fonts once per window. This means that opening a new tab is fast, and switching tabs in the same window is also fast. (There's still work to do to share fonts across windows, or to reduce the time it takes to initialize these fonts.)
The performance of deeply-nested display: grid elements is greatly improved.
Support for profiling multiple java threads has been added.
Soft-reloading a web page will no longer cause revalidation for all resources.
Non-vsync tasks are given more time to run, which improves behavior on Google docs and Twitch.
Geckoview APIs have been added to control the start/stop time of capturing a profile.
Changed:
Firefox has a new focus indicator for links which replaces the old dotted outline with a solid blue outline. This change unifies the focus indicators across form fields and links, which makes it easier to identify the focused link, especially for users with low vision.
New users can now set Firefox as the default PDF handler when setting Firefox as their default browser.
Some websites might not work correctly in Firefox version 100 due to Firefox's new three-digit number. You can read about it in our blog post here!
See the Mozilla Support article Difficulties opening or using a website in Firefox 100 for possible workarounds you can use. There, you will also find instructions for reporting a broken website so that Mozilla can help fix the problem.
Mozilla Support articles for Desktop and Android:
https://support.mozilla.org/kb/difficulties-opening-or-using-website-firefox-100
https://support.mozilla.org/kb/difficulties-firefox-android-100
Web Platform:
Support for the WritableStream API has landed. WritableStreams provide an interface for writing streaming data to a sink object.
Additionally, ReadableStream gained support for the “pipeTo” method, which allows you to connect a ReadableStream to a WritableStream. For example, this would allow you to process data retrieved using “fetch” with the WritableStream Sink object.
Support for WASM Exceptions is now available. This allows C++ exception handling and unwinding/destructing semantics to be expressed in WASM without an additional JavaScript helper code—and at zero cost to code that does not rely on exception semantics.

New in Firefox 99.0.1 (Apr 12, 2022)

New in Firefox 99.0 (Apr 5, 2022)

New in Firefox 98.0.2 (Mar 23, 2022)

New in Firefox 98.0.1 (Mar 14, 2022)

New in Firefox 98.0 (Mar 8, 2022)

New:
Firefox has a new optimized download flow. Instead of prompting every time, files will download automatically. However, they can still be opened from the downloads panel with just one click. Easy!
You’ll find you have a number of options, including:
Always Open Similar Files: Make Firefox automatically open downloaded files of the same type with the system default application.
Show In Folder: Open the folder that contains your downloaded files.
Go To Download Page: Surfaces the download reference page even after leaving the site or closing the tab.
Copy Download Link: Copy the download link to share it, save it, or for any applicable use.
Delete: You can now delete downloaded files directly from the download panel and other download views using the context menu.
Remove From History: Remove a file from your list of downloaded files.
Clear Preview Panel: Clear the list of downloaded items in the preview panel that opens when you start a download.
In this release, you’ll also see that Firefox no longer asks what to do for each file by default. You won’t be prompted to choose a helper application or save to disk before downloading a file unless you have changed your download action setting for that type of file.
And now, every time you start a download, Firefox will automatically bring up the Downloads panel by default. This means you’ll experience minimal interruptions and easily find your downloaded files. Plus, to avoid having to close it several times, the panel won't show if there are multiple downloads in progress.
You can now click on a file in the Downloads panel to open it even before it has finished downloading. Firefox will open the file as soon as it is available. Firefox: saving you time and helping you get back to what you care about!
Any files you download will be immediately saved on your disk. Depending on the current configuration, they’ll be saved in your preferred download folder, or you’ll be asked to select a location for each download. Windows and Linux users will find their downloaded files in the destination folder. They’ll no longer be put in the Temp folder.
Firefox allows users to choose from a number of built-in search engines to set as their default. In this release, some users who had previously configured a default engine might notice their default search engine has changed since Mozilla was unable to secure formal permission to continue including certain search engines in Firefox.
Fixed:
Now, you can set a default app to open a file type. Choose the application you want to use to open files of a specific type in your Firefox settings.
After updating to Firefox version 98, "Always ask" download actions will now be reset.
Various security fixes.

New in Firefox 97.0.2 (Mar 7, 2022)

New in Firefox 97.0.1 (Feb 17, 2022)

New in Firefox 97.0 (Feb 9, 2022)

New in Firefox 96.0.3 (Jan 27, 2022)

New in Firefox 96.0.2 (Jan 20, 2022)

New in Firefox 96.0.1 (Jan 20, 2022)

New in Firefox 96.0 (Jan 11, 2022)

New in Firefox 95.0 (Dec 7, 2021)

New in Firefox 94.0.2 (Nov 23, 2021)

New in Firefox 94.0.1 (Nov 4, 2021)

New in Firefox 94.0 (Nov 2, 2021)

New:
With 94, you’ll find a selection of six fun seasonal Colorways (available for a limited time only). Now you can find a color to suit (or lift) your every mood.
Fun fact: Did you know we have more daily users with color themes than dark or Alpenglow on Beta? With Firefox 89, 32% of users clicked through to customize their color theme. And that was just on the first day! We decided to introduce these new Colorways to give our users more to love.
Firefox macOS now uses Apple's low power mode for fullscreen video on YouTube and Twitch. This meaningfully extends battery life in long viewing sessions. Now your kids can find out what the fox says on a loop without you ever missing a beat…
With this release, power users can use about:unloads to release system resources by manually unloading tabs without closing them.
On Windows, there will now be fewer interruptions because Firefox won’t prompt you for updates. Instead, a background agent will download and install updates even if Firefox is closed.
To better protect all Firefox users against side-channel attacks such as Spectre, we’ve introduced Site Isolation. We’ve got your back...errr...side!
We’re rolling out the Firefox Multi-Account Containers extension with Mozilla VPN integration. This lets you use a different server location for each container.
Firefox no longer warns you by default when you exit the browser or close a window using a menu, button, or three-key command. This should cut back on unwelcome notifications which is always nice--however, if you prefer a bit of notice, you’ll still have full control over the quit/close modal behavior. All warnings can be managed within Firefox Settings. No worries! (More details)
And now, Firefox supports the new Snap Layouts menus when running on Windows 11.
Fixed:
We’ve reduced the overhead of using performance.mark() and performance.measure() APIs with a large set of performance entries.
Plus, we’ve modified paint suppression during load to greatly improve warmload performance in Site Isolation mode.
You’ll also notice a small reduction in Javascript memory usage.
With this release, you’ll notice faster Javascript property enumeration as well.
We’ve also implemented better scheduling of garbage collection which has improved some pageload benchmarks.
This release also sees reduced CPU usage during socket polling for HTTPS connections.
Additionally, you’ll notice faster storage initialization.
We’ve also improved cold startup by reducing main thread I/O.
Plus, closing devtools now reclaims more memory than ever before.
And we’ve improved pageload (especially with Site Isolation mode) by setting a higher priority for loading and displaying images.
Various security fixes
Enterprise:
Enterprise users now have more control over Firefox deployments with the availability of our MSIX package on Windows platforms.
You’ll also notice various bug fixes and new policies have been implemented in this latest version of Firefox.

New in Firefox 93.0 (Oct 5, 2021)

New in Firefox 92.0.1 (Oct 5, 2021)

New in Firefox 92.0 (Sep 7, 2021)

New in Firefox 91.0.2 (Aug 24, 2021)

New in Firefox 91.0.1 (Aug 17, 2021)

New in Firefox 91.0 (Aug 10, 2021)

New in Firefox 90.0.2 (Jul 22, 2021)

New in Firefox 90.0.1 (Jul 19, 2021)

New in Firefox 90.0 (Jul 13, 2021)

New in Firefox 89.0.2 (Jun 23, 2021)

New in Firefox 89.0.1 (Jun 16, 2021)

New in Firefox 89.0 (Jun 1, 2021)

New:
Say hello to a fresh new Firefox, designed to get you where you want to go even faster. We’ve redesigned and modernized the core experience to be cleaner, more inviting, and easier to use.
Beginning in 89, you’ll notice a number of changes, including:
Simplified browser chrome and toolbar: Less frequently used items removed to focus on the most important navigation items.
Clear, streamlined menus: Re-organized and prioritized menu content according to usage. Updated labels and removed iconography.
Updated prompts: Infobars, panels, and modals have a cleaner design and clearer language.
Inspired tab design: Floating tabs neatly contain information and surface cues when you need them, like visual indicators for audio controls. The rounded design of the active tab supports focus and signals the ability to easily move the tab as needed.
Fewer interruptions: Reduced number of alerts and messages, so you can browse with fewer distractions.
Cohesive, calmer visuals: Lighter iconography, a refined color palette, and more consistent styling throughout.
This release also includes enhancements to our privacy offerings:
We’ve enhanced the privacy of the Firefox Browser’s Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companies from using cookies to track your browsing across sites. This feature was originally launched in Firefox’s ETP Strict mode.
macOS:
For macOS users, we're introducing the elastic overscroll effect known from many other applications. A gentle bouncing animation will indicate that you reached the end of the page.
In addition, we added support for smart zoom. Double-tap with two fingers on your trackpad, or with a single finger on your Magic Mouse, to zoom the content below your cursor into focus.
Native context menus: Context menus on macOS are now native and support Dark Mode.
Fixed:
Colors in Firefox on macOS will no longer be saturated on wide gamut displays, untagged images are properly treated as sRGB, and colors in images tagged as sRGB will now match CSS colors.
In full screen mode on macOS, moving your mouse to the top of the screen will no longer hide your tabs behind the system menu bar.
Also in full screen mode on macOS, it is now possible to hide the browser toolbars for a fully immersive full screen experience. This brings macOS in line with Windows and Linux.
Various stability and security fixes.
Changed:
Introducing a non-native implementation of web form controls, which delivers a new modern design and some improvements to page load performance. Watch for layout bugs in web pages that make assumptions about the dimensions or styling of form controls.
The screenshots feature is available in the right-click context menu. You can also add a screenshots shortcut to your toolbar.
Developer:
Better keyboard navigation for editable BoxModel properties in the Inspector panel
Web Platform:
The Event Timing API is now supported.
The CSS forced-colors media query is now supported.

New in Firefox 88.0.1 (May 6, 2021)

New in Firefox 89.0 Beta (Apr 23, 2021)

New:
Say hello to a fresh new Firefox, designed to get you where you want to go even faster. We’ve redesigned and modernized the core experience to be cleaner, more inviting, and easier to use.
Beginning in 89, you’ll notice a number of changes, including:
Simplified browser chrome and toolbar: Redundant or less frequently used features have been removed to focus on the most important navigation items.
Streamlined menus: Content has been re-organized and prioritized according to usage. We’ve reduced visual noise by removing unnecessary iconography and provided clearer labels.
Updated prompts: Infobars and modals have a cleaner design and clearer language.
Inspired new tab design: Floating tabs neatly contain information and surface cues when you need them, like visual indicators for audio controls. The rounded design of the active tab supports focus and signals the ability to easily move the tab as needed.
Fewer interruptions: We’ve removed unnecessary alerts and messages.
Cohesive, calmer visuals: Lighter iconography, a refined color palette, and more consistent styling throughout.
This release also includes enhancements to our privacy offerings:
We’ve enhanced the privacy of the Firefox Browser’s Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companies from using cookies to track your browsing from site to site. This feature was previously available only in Firefox’s ETP Strict mode.
We are rolling out Version 2 of our existing SmartBlock feature, which enables a seamless web page experience that would otherwise stop working when we block trackers.
Fixed:
Colors in Firefox on macOS will no longer be saturated on wide gamut displays, untagged images are properly treated as sRGB, and colors in images tagged as sRGB will now match CSS colors.
Changed:
Introducing a non-native implementation of web form controls, which delivers a new modern design and some improvements to page load performance. Watch for layout bugs in web pages that make assumptions about the dimensions or styling of form controls.
Web Platform:
The Event Timing API is now supported.

New in Firefox 88.0 (Apr 19, 2021)

New in Firefox 88.0 Beta 8 (Apr 8, 2021)

New in Firefox 87.0 (Mar 23, 2021)

New:
You’ll encounter less website breakage in Private Browsing and Strict Enhanced Tracking Protection with SmartBlock, which provides stand-in scripts so that websites load properly.
To further protect your privacy, our new default HTTP Referrer policy will trim path and query string information from referrer headers to prevent sites from accidentally leaking sensitive user data.
The “Highlight All” feature on Find in Page now displays tick marks alongside your scrollbar that correspond to the location of matches found on that page.
We’re proud to announce full support for macOS built-in screen reader, VoiceOver.
We’ve added a new locale: Silesian (szl)
Fixed:
We’ve fixed several significant accessibility issues
Video controls now have visible focus styling and video and audio controls are now keyboard navigable. (Bug 1681007)
HTML is now spoken by screen readers. (Bug 1460378)
Firefox now sets a useful initial focus in Add-ons Manager. (Bug 580537)
Firefox will now fire a name/description change event when aria-labelledby/describedby content changes. (Bug 493683)
Various security fixes.
Changed:
To prevent user data loss when filling out forms, we’ve disabled the Backspace key as a navigation shortcut for the back navigation button. To re-enable the Backspace keyboard shortcut, you can change the about:config preference browser.backspace_action to 0. You can also use the recommended Alt + Left arrow (Command + Left arrow on Mac) shortcut instead.
Firefox keyboard shortcuts
We've removed items from the Library menu that weren't used often or have other access points in the browser: Synced tabs, Recent highlights, and Pocket list.
We've simplified the Help menu by reducing redundant items, such as those that point to Firefox support pages that can also be accessed via the Get Help item.
Enterprise:
Various bug fixes and new policies have been implemented in the latest version of Firefox.
Developer:
We've greatly simplified the Web Developer menu. Go to Application Menu > Web Developer > Web Developer Tools to access Inspector, Web Console, Debugger, Network Style Error, Performance, Storage Inspector, Accessibility, and Application
Developers can now use the Page Inspector to simulate prefers-color-scheme media queries, without having to change the operating system to light or dark mode.
Developers can now use the Page Inspector to toggle the :target pseudo-class for the currently selected element in addition to the pseudo-classes that were previously supported: :hover, :active and :focus, :focus-within, :focus-visible, and :visited.
There is a number of Page Inspector improvements and bug fixes related to inactive CSS rules:
The table-layout property is now marked as inactive for non-table elements.
The scroll-padding properties (shorthand and longhand) are now marked as inactive for non-scrollable elements.
The text-overflow property was previously incorrectly marked as inactive for some overflow values.

New in Firefox 86.0.1 (Mar 11, 2021)

New in Firefox 86.0 (Feb 23, 2021)

New in Firefox 85.0.2 (Feb 9, 2021)

New in Firefox 85.0.1 (Feb 5, 2021)

New in Firefox 85.0 (Jan 26, 2021)

New in Firefox 84.0.2 (Jan 6, 2021)

New in Firefox 84.0.1 (Dec 23, 2020)

New in Firefox 84.0 (Dec 15, 2020)

New in Firefox 84.0 Beta (Dec 2, 2020)

New in Firefox 83.0 (Nov 17, 2020)

New:
Firefox keeps getting faster as a result of significant updates to SpiderMonkey, our JavaScript engine, you will now experience improved page load performance by up to 15%, page responsiveness by up to 12%, and reduced memory usage by up to 8%. We have replaced part of the JavaScript engine that helps to compile and display websites for you, improving security and maintainability of the engine at the same time.
Firefox introduces HTTPS-Only Mode. When enabled, this new mode ensures that every connection Firefox makes to the web is secure and alerts you when a secure connection is not available. You can enable it in Firefox Preferences.
Pinch zooming will now be supported for our users with Windows touchscreen devices and touchpads on Mac devices. Firefox users may now use pinch to zoom on touch-capable devices to zoom in and out of webpages.
Picture-in-Picture now supports keyboard shortcuts for fast forwarding and rewinding videos: use the arrow keys to move forward and back 15 seconds, along with volume controls. For a list of supported commands see Support Mozilla
When you are presenting your screen on a video conference in Firefox, you will see our improved user interface that makes it clearer which devices or displays are being shared.
Firefox supports AcroForm, which will allow you to fill in, print, and save supported PDF forms and the PDF viewer also has a new fresh look.
Our users in India on the English build of Firefox will now see Pocket recommendations in their new tab featuring some of the best stories on the web. If you don’t see them, you can turn on Pocket articles in your new tab by following these steps.
For the recently released Apple devices built with Apple Silicon CPUs, you can use Firefox 83 and future releases without any change. This release (83) will support emulation under Apple’s Rosetta 2 that ships with macOS Big Sur. We are working toward Firefox being natively-compiled for these CPUs in a future release.
This is a major release for WebRender as we roll out to more Firefox users on Windows 7 and 8 as well as on macOS 10.12 to 10.15.
We’ve improved functionality and design for a number of Firefox search features:
Selecting a search engine at the bottom of the search panel now enters search mode for that engine, allowing you to see suggestions (if available) for your search terms. The old behavior (immediately performing a search) is available with a shift-click.
When Firefox autocompletes the URL of one of your search engines, you can now search with that engine directly in the address bar by selecting the shortcut in the address bar results.
We’ve added buttons at the bottom of the search panel to allow you to search your bookmarks, open tabs, and history.
Fixed:
For users on macOS restoring a session with minimized windows, Firefox now uses much less power and you should see much longer battery life.
Various security fixes
This release also includes a number of accessibility fixes:
Screen reader features which report paragraphs now correctly report paragraphs instead of lines in Google Docs
When reading by word using a screen reader, words are now correctly reported when there is punctuation nearby
The arrow keys now work correctly after tabbing in the picture-in-picture window
Developer:
Developers can use the scroll badge in the Page Inspector to Debug scrollable overflow. Selecting the badge highlights elements that are causing overflow and marks them with the overflow badge
Web Platform:
This release adds support for conic gradients in CSS, helping colors to smoothly transition as you spin around the center, rather than as you progress outward from the center.

New in Firefox 82.0.3 (Nov 9, 2020)

New in Firefox 82.0.2 (Oct 28, 2020)

New in Firefox 82.0 (Oct 20, 2020)

New in Firefox 81.0.2 (Oct 13, 2020)

New in Firefox 81.0.1 (Oct 1, 2020)

New in Firefox 81.0 (Sep 22, 2020)

New:
You can pause and play audio or video in Firefox right from your keyboard or headset, giving you easy access to control your media when in another Firefox tab, another program, or even when your computer is locked.
In addition to our default, dark and light themes, with this release, Firefox introduces the Alpenglow theme: a colorful appearance for buttons, menus, and windows. You can update your Firefox themes under settings or preferences.
For our users in the US and Canada, Firefox can now save, manage, and auto-fill credit card information for you, making shopping on Firefox ever more convenient. To ensure the smoothest experience, this will be rolling out to users gradually.
Firefox supports AcroForm, which will soon allow you to fill in, print, and save supported PDF forms and the PDF viewer also has a new fresh look.
Our users in Austria, Belgium and Switzerland using the German version of Firefox will now see Pocket recommendations in their new tab featuring some of the best stories on the web. If you don’t see them, you can turn on Pocket articles in your new tab by following these steps. In addition to Firefox’s new tab, Pocket is also available as an app on iOS and Android.
Fixed:
Various security fixes.
We’ve fixed a bug for users of language packs where the default language was reset to English after Firefox updates.
Browser native HTML5 audio/video controls received several important accessibility fixes:
Audio/video controls remain accessible to screen readers even when they are temporarily hidden visually.
Audio/video elapsed and total time are now accessible to screen readers where they weren't previously.
Various unlabelled controls are now labelled making them identifiable to screen readers.
Screen readers no longer intrusively report progress information unless the user requests it.
Changed:
You will soon find Picture-in-Picture more easily on all the videos you watch with new iconography.
The bookmarks toolbar is now automatically revealed once bookmarks are imported into Firefox, making it easier to find your most important websites.
We have expanded our supported file types - .xml, .svg, and .webp - so files you’ve downloaded can be opened right in Firefox.
Enterprise:
Various bug fixes and new policies have been implemented in the latest version of Firefox. You can see more details in the Firefox for Enterprise 81 Release Notes.
Developer:
TypeScript files are now properly identified in the Debugger panel and labeled with corresponding icons making it easier for you to find these files in the list.
HTTP JSON responses using XSSI prevention characters are properly parsed and JSON data presented in a form of an expandable tree. This allows easy inspection of such HTTP responses through traditional (expandable) tree UI.
It’s possible to pause on script first statement, which is useful e.g. in cases where developers want to debug side effects caused by script execution or timers.
The color vision deficiency simulation in the accessibility panel of Developer Tools is now more accurate. We removed protanomaly, deuteranomaly and tritanomaly and aded achromatopsia.

New in Firefox 80.0.1 (Sep 1, 2020)

New in Firefox 80.0 (Aug 27, 2020)

New:
Firefox can now be set as the default system PDF viewer.
The name reported by accessibility tools for items in multi-tiered tree controls no longer incorrectly includes information from items at deeper levels, providing users with the correct level of content when using a screen reader.
Fixed:
Various security fixes.
Several crashes while using a screen reader were fixed including a frequently encountered crash when using the JAWS screen reader.
Firefox Developer Tools received significant fixes allowing screen reader users to benefit from some of the tools that were previously inaccessible.
SVG title and desc elements (labels and descriptions) are now correctly exposed to assistive technology products such as screen readers.
Changed:
For users with reduced motion settings, we’ve reduced a number of animations such as tab loading to reduce motion for users with migraines and epilepsy.
The new add-ons blocklist has been enabled to improve performance and scalability.
Enterprise:
A number of bug fixes and new policies have been implemented in the latest version of Firefox. You can see more details in the Firefox for Enterprise 80 Release Notes.
Today’s release is the final scheduled for Firefox 68 ESR (68.12) unless there is a critical security issue found prior to the release of Firefox ESR 78.3 on September 22, 2020. Users of Firefox 68 ESR will be automatically upgraded to the Firefox 78 ESR series with the release of 78.3.
Developer:
Developer Information
We’ve shipped an experimental sidebar panel in the inspector to Firefox Developer Edition that helps developers more quickly identify potential browser compatibility problems based on MDN data.
In the Network Monitor request list, a turtle icon is shown for "slow" requests that exceed a threshold for the waiting time.
Firefox now supports RTX and Transport-cc for improved call quality in poor network conditions and better bandwidth estimation. These features also provide better compatibility with many websites using WebRTC.

New in Firefox 79.0 (Jul 28, 2020)

New:
We’ve rolled out WebRender to more Windows users with Intel and AMD GPUs, bringing improved graphics performance to an even larger audience.
Firefox users in Germany will now see more Pocket recommendations in their new tab featuring some of the best stories on the web. If you don’t see them, you can turn on Pocket articles in your new tab by following these steps.
Fixed:
Various security fixes.
Several crashes while using a screen reader were fixed, including a frequently encountered crash when using the JAWS screen reader.
Firefox Developer Tools received significant fixes allowing screen reader users to benefit from some of the tools that were previously inaccessible.
SVG title and desc elements (labels and descriptions) are now correctly exposed to assistive technology products such as screen readers.
Enterprise:
A number of bug fixes and new policies have been implemented in the latest version of Firefox. You can see more details in the Firefox for Enterprise 79 Release Notes.
Updates to the password policy allow admins to require a primary password (formerly called master password. Previously the policy could disable the primary password but not force a primary password. Users required to use a primary password will only be asked to create a primary password the first time they try to save a password.
Developer:
Newly added asynchronous call stacks let developers trace their async code through events, timeouts, and promises. The async execution chains are shown in the Debugger’s call stack, but also for stack traces in Console errors and Network initiators.
Erroneous network responses with 4xx/5xx status codes display as errors in the Console, making it easy to understand them in the context of related logs. The request/response details can be expanded or resent for quick debugging.
JavaScript errors are now visible not only in the Console, but also in the Debugger. The relevant line of code will be highlighted and display error details on hover.
Opening SCSS and CSS-in-JS sources from the Inspector now works more reliably thanks to improved source map handling across all panels.
Inspecting accessibility properties from the browser context menu is now available to all users by default.

New in Firefox 78.0.2 (Jul 9, 2020)

New in Firefox 78.0.1 (Jul 2, 2020)

New in Firefox 78.0 (Jun 30, 2020)

New:
The Protections Dashboard includes consolidated reports about tracking protection, data breaches, and password management.
New features let you:
Track how many breaches you’ve resolved right from the dashboard.
See if any of your saved passwords may have been exposed in a data breach
To view your dashboard, type about:protections into the address bar, or select “Protections Dashboard” from the main menu.
Because we know people try to fix problems by reinstalling Firefox when a simple refresh is more likely to solve the issue, we’ve added a Refresh button to the Uninstaller.
With this release, your screen saver will no longer interrupt WebRTC calls on Firefox, making conference and video calling in Firefox better.
We’ve rolled out WebRender to Windows users with Intel GPUs, bringing improved graphics performance to an even larger audience.
Firefox 78 is also our Extended Support Release (ESR), where the changes made over the course of the previous 10 releases will now roll out to our ESR users. Some of the highlights are:
Kiosk mode
Client certificates
Service Worker and Push APIs are now enabled
The Block Autoplay feature is enabled
Picture-in-picture support
View and manage web certificates in about:certificate
Pocket recommendations, featuring some of the best stories on the web, will now appear on the Firefox new tab for 100% of our users in the UK. If you don’t see them, you can turn on Pocket articles in your new tab, follow these steps.
Fixed:
Various security fixes.
We fixed bugs in the search results quality composition and improved search result texts based on recommendations by our partners.
Changed:
The minimal system requirements on Linux have been updated. Firefox now needs GNU libc 2.17, libstdc++ 4.8.1 and GTK+ 3.14 or newer versions.
As part of our ongoing effort to deprecate obsolete cryptography, we have disabled all remaining DHE-based TLS ciphersuites by default.
To mitigate web compatibility issues from disabling DHE-based TLS ciphersuites, Firefox 78 enables two more AES-GCM SHA2-based ciphersuites.
We have disabled TLS 1.0 and TLS 1.1 to improve your website connections. Sites that don't support TLS version 1.2 will now show an error page.
The context menu (accessed by right clicking on a tab) lets you undo multiple tab closings with a single click and places Close Tabs to the Right and Close Other Tabs in a submenu.
A number of accessibility improvements have been made with this release:
When using the JAWS screen reader, pressing the down arrow in an HTML input control with a datalist no longer incorrectly moves the cursor to the next element after the input control.
Screen readers no longer severely lag or freeze when focusing the microphone/camera/screen sharing indicator.
Large tables with thousands of rows now load much faster for screen reader users.
Text input controls with custom styling now correctly show the focus outline when appropriate.
Screen readers no longer sometimes incorrectly switch to document browsing mode unexpectedly when the user enters the main Developer Tools window.
We reduced a number of animations such as tab hover, search bar expansion, and others to reduce motion for users with migraines and epilepsy.
Enterprise:
Enable support for client certificates stored on macOS and Windows by setting the experimental preference security.osclientcerts.autoload to true.
New policies allow you to configure application handlers, disable picture in picture, and require a master password, which will be renamed to ‘primary password’ in future releases.
Developer:
DevTools Console now logs uncaught promise errors with much more detailed names, stacks, and properties, particularly improving JavaScript framework debugging.
Debugger’s automatic mapping for minified variable names now also works for Logpoints, which makes debugger of source-mapped projects feel more seamless.
The Firefox DevTools’ Network panel now highlights which extension or CORS restriction blocked a request, so developers can make their sites more resilient and secure.
New RegExp engine in SpiderMonkey, adding support for the dotAll flag, Unicode escape sequences, lookbehind references, and named captures.

New in Firefox 77.0.1 (Jun 4, 2020)

New in Firefox 77.0 (Jun 3, 2020)

New in Firefox 76.0.1 (May 10, 2020)

New in Firefox 76.0 (May 5, 2020)

New in Firefox 75.0 (Apr 7, 2020)

New in Firefox 74.0 (Mar 10, 2020)

New in Firefox 73.0.1 (Feb 19, 2020)

New in Firefox 73.0 (Feb 18, 2020)

New:
Today’s Firefox release includes two features that help users view and read website content more easily, quickly. Like all accessibility improvements, these features improve browsing for everyone.
Firefox has offered a page zoom feature for more than a decade that allows users to set the zoom level on a per-site basis. For users who need to zoom most websites, having to adjust zoom for each new site can be an annoyance. To address this, we have implemented a new global default zoom level setting. This option is available in about:preferences under "Language and Appearance" and can be scaled up or down from 100% as needed and sets the default zoom level for all sites. Per-site zoom is still available to make adjustments to individual sites as needed.
Many users with low vision rely on Windows' High Contrast Mode to make websites more readable. Traditionally, to increase the readability of text, Firefox has disabled background images when High Contrast Mode is enabled. With today’s release of Firefox 73, we introduce a “readability backplate” solution which places a block of background color between the text and background image. Now, websites in High Contrast Mode are more readable without disabling background images.
Fixed:
Various security fixes.
Improved audio quality when playing back audio at a faster or slower speed.
Firefox will now only prompt you to save logins if a field in a login form was modified.
Changed:
WebRender rollout has been expanded to include Windows 10 laptops running NVIDIA graphics cards with drivers newer than 432.00 and screen sizes smaller than 1920x1200.
Developer:
WAMP-formatted WebSocket messages (JSON, MsgPack and CBOR) are now nicely decoded for inspection in the Network panel.
Web Platform:
Improved auto-detection of legacy text encodings on old web pages which don’t explicitly declare the text encoding.
Unresolved:
Users with 0patch security software may encounter crashes at startup after updating to Firefox 73. This will be fixed in a future Firefox release. As a workaround, an exclusion for firefox.exe can be added within the 0patch settings.

New in Firefox 72.0.2 (Jan 22, 2020)

New in Firefox 72.0.1 (Jan 20, 2020)

New in Firefox 72.0 (Jan 8, 2020)

New in Firefox 71.0 (Dec 4, 2019)

New:
Improvements to Lockwise, our integrated password manager:
Firefox now recognizes subdomains and will autofill domain logins from Lockwise
Integrated breach alerts from Firefox Monitor are now available to users with screen readers
More information about Enhanced Tracking Protection in action:
Notifications when Firefox blocks cryptominers
A running tally of blocked trackers in the protection panel accessed by clicking the address bar shield
Picture-in-picture video comes to Firefox for Windows: Select the blue icon from the right edge of a video to pop open a floating window so you can keep watching while working in other tabs. Learn how the feature works.
Native MP3 decoding on Windows, Linux, and macOS
Fixed:
Various security fixes.
Changed:
Configuration page (about:config) reimplemented in HTML
Firefox will now ship with Catalan (Valencian) (ca-valencia), Tagalog (tl), and Triqui (trs)
Enterprise:
New kiosk mode functionality, which allows maximum screen space for customer-facing displays
Developer:
New videos every week on the Mozilla Developer YouTube channel
Improvements to the website certificate viewer, with more features and more detailed information
Improvements to the extensions downloads API for handling download failures
Extension popup windows now include the extension name instead of its moz-extension:// url when using the windows.create API
Extension-registered devtools panels now interact better with screen readers
Added support for developers, including:
DevTools’ Network panel can now inspect WebSocket messages and automatically formats a variety of framework formats
Console’s new multi-line editor mode provides an IDE-like experience that makes it convenient to iterate on longer code snippets
The Network panel’s new resource blocking can simulate the impact of tracking protection, security, service outages, and bad connectivity for more robust testing
More features and improvements can be found every release in DevTools’ “What’s New” panel in en-US

New in Firefox 70.0.1 (Nov 1, 2019)

New in Firefox 70.0 (Oct 24, 2019)

New:
More privacy protections from Enhanced Tracking Protection:
Social tracking protection, which blocks cross-site tracking cookies from sites like Facebook, Twitter, and LinkedIn, is now a standard feature of Enhanced Tracking Protection.
The Privacy Protections report shows an overview, with details, of the trackers Firefox has blocked. It provides consolidated reports from Monitor and Lockwise.
More security protections from Firefox Lockwise, our digital identity and password management tool:
Lockwise for desktop lets you create, update, and delete your logins and passwords to sync across all your devices, including the Lockwise mobile apps and Firefox mobile browsers .
Integrated breach alerts from Firefox Monitor, to alert you when saved logins and passwords are compromised in online data breaches.
Complex password generation, to help you create and save strong passwords for new online accounts.
Improvements to core engine components, for better browsing on more sites:
A faster Javascript Baseline Interpreter to handle the modern web’s
large codebases and improve page load performance by as much as 8
percent.
WebRender rolled out to more Firefox for Windows users, now available by default on Windows desktops with integrated Intel graphics cards and resolution of 1920x1200 or less) for improved graphics rendering.
Compositor improvements in Firefox for macOS that reduce power
consumption, speed up page load by as much as 22 percent, and reduce
resource use for video by up to 37 percent.
More browser features to help you get the most out of Firefox products and services:
A stand-alone Firefox account menu for easy access to Firefox services like Monitor and Send.
A message panel accessed from the gift icon in the toolbar that offers a quick overview of new releases and key features.
When a website uses your geolocation, an indicator is shown in the
address bar.
Fixed:
Various security fixes
Changed:
Built-in Firefox pages now follow the system dark mode preference
Aliased theme properties have been removed, which may affect some themes
Passwords can now be imported from Chrome on macOS in addition to existing support for Windows
Readability is now greatly improved on under- or overlined texts, including links. The lines will now be interrupted instead of crossing over a glyph.
Improved privacy and security indicators:
A new crossed-out lock icon will indicate sites delivered via
insecure HTTP
The formerly green lock icon is now grey
The Extended Validation (EV) indicator has been moved to the identity
popup that appears when clicking the lock icon
Developer:
For additional developer resources from Mozilla, visit our Mozilla Developer YouTube channel for new videos every week.
The Developer Tools Accessibility panel now includes an audit for keyboard accessibility and a color deficiency simulator for systems with WebRender enabled
Inactive CSS: The Inspector now grays out CSS declarations that don’t affect the selected element and shows a tooltip explaining why -- and even how to fix it.
The new DOM Mutation Breakpoints in Developer Tools allows developers to diagnose when scripts add, remove or update page content. This makes debugging of complex script interactions and dependencies a lot easier.
WebExtensions developers can now inspect browser.storage.local data using the "Addon Debugging" Firefox Developer Tools.
With new network resource search in Developer Tools, you can quickly find resources based on their request and response data, including headers, cookies and content.

New in Firefox 69.0.3 (Oct 11, 2019)

New in Firefox 69.0.1 (Oct 3, 2019)

New in Firefox 69.0 (Sep 18, 2019)

New:
Enhanced Tracking Protection (ETP) rolls out stronger privacy protections:
The default standard setting for this feature now blocks third-party tracking cookies and cryptominers.
The optional strict setting blocks fingerprinters as well as the items blocked in the standard setting.
The Block Autoplay feature is enhanced to give users the option to block any video that automatically starts playing, not just those that automatically play with sound.
For our users in the US or using the en-US browser, we are shipping a new “New Tab” page experience that connects you to the best of Pocket’s content.
Support for the Web Authentication HmacSecret extension via Windows Hello now comes with this release, for versions of Windows 10 May 2019 or newer, enabling more passwordless experiences on the web.
Support for receiving multiple video codecs with this release makes it easier for WebRTC conferencing services to mix video from different clients.
For our users on Windows 10, you’ll see performance and UI improvements:
Firefox will give Windows hints to appropriately set content process priority levels, meaning more processor time spent on the tasks you're actively working on, and less processor time spent on things in the background (with the exception of video and audio playback).
For our existing Windows 10 users, you can easily find and launch Firefox from a shortcut on the Win10 taskbar.
For our users on macOS, battery life and download UI are both improved:
macOS users on dual-graphics-card machines (like MacBook Pro) will switch back to the low-power GPU more aggressively, saving battery life.
Finder on macOS now displays download progress for files being downloaded.
JIT support comes to ARM64 for improved performance of our JavaScript Optimizing JIT compiler.
Fixed:
Various security fixes
Changed:
As previously announced in the Plugin Roadmap for Firefox, the "Always Activate" option for Flash plugin content has been removed. Firefox will now always ask for user permission before activating Flash content on a website.
With the deprecation of Adobe Flash Player, there is no longer a need to identify users on 32-bit version of the Firefox browser on 64-bit version operating systems reducing user agent fingerprinting factors providing greater level of privacy to our users as well as improving the experience of downloading other apps.
Firefox no longer loads userChrome.css or userContent.css by default improving start-up performance. Users who wish to customize Firefox by using these files can set the toolkit.legacyUserProfileCustomizations.stylesheets preference to true to restore this ability.
Enterprise:
For Enterprise system administrators that manage macOS computers, we begin shipping a Mozilla signed PKG installer to simplify your deployments.
Developer:
For our mobile web developers, we have migrated remote debugging from the old WebIDE into a re-designed about:debugging, making debugging GeckoView on remote devices via USB rock solid.
The network panel will now show blocked resources to allow developers to best understand the impact of content blocking and ad blocking extensions given our ongoing expansion of Enhanced Tracking Protection to all users with this release.
The new event listener breakpoint feature allows developers to pause on a host of different event types, whether it be related to animations, DOM, media, mouse, touch, worker, and many other event types.
Firefox Developer Tools now offers an audit for the presence of text alternatives for non-text content, the a11y panel checks toolbar has been augmented to better help developers adhere to WCAG Guideline 1.1.

New in Firefox 68.0.2 (Aug 16, 2019)

New in Firefox 68.0.1 (Jul 19, 2019)

New in Firefox 68.0 (Jul 12, 2019)

New:
Dark mode in reader view expands so that windows are also dark on the controls, sidebars and toolbars.
Cryptomining and fingerprinting protections are added to strict content blocking settings in Privacy & Security preferences.
WebRender will roll out to Windows 10 users with AMD graphics cards.
Windows Background Intelligent Transfer Service (BITS) update download support, which allows Firefox update downloads to continue when Firefox is closed.
Improved extension security and discovery:
New reporting feature in about:addons allows you to report security and performance issues with extensions and themes.
Redesigned extensions dashboard in about:addons provides easy access to information about your extensions, including data and settings access required by each extension.
Find high quality, secure extensions via the Recommended Extensions program in about:addons, which now displays user count and ratings for each extension. "Recommended” badges for these extensions also appear on AMO. More extensions will be added over time.
Fixed:
Various security fixes
Local files can no longer access other files in the same directory.
Changed:
Unified existing locales (bn-BD, bn-IN) under a single Bengali (bn) localization.
The following unmaintained translations have been removed: Assamese (as), English - South Africa (en-ZA), Maithili (mai), Malayalam (ml), Odia (or). Existing users will be migrated to the British English (en-GB) version.
When an HTTPS error caused by antivirus software is detected, Firefox will attempt to automatically fix it
Camera and microphone access now require an HTTPS connection.
The way non-default preferences are synced has changed. Please see this support article for more details
Enterprise:
For all operating systems, we have a number of additional policies including:
New tab page configuration and disabling
Local file links
Download behavior
Search suggestions
Managed storage for using policies in Webextensions
Extension whitelisting and blacklisting by ID and website
A subset of commonly used Firefox preferences
Developer:
Firefox Developer Tools now offers a full page color contrast audit that identifies all elements on a page that fail color contrast checks.
Added about:compat, where website-specific workarounds are listed and may be toggled. These workarounds are meant as temporary fixes for various forms of website breakage for Firefox, while the website fixes them in due time. With about:compat, it is now easy to see all of the workarounds that are active in Firefox, and easy for website developers to disable a given workaround for testing purposes.
Introduces CSS Scroll Snap module that enforces scroll snap positions.

New in Firefox 67.0.4 (Jun 21, 2019)

New in Firefox 67.0.3 (Jun 19, 2019)

New in Firefox 67.0.2 (Jun 17, 2019)

New in Firefox 67.0 (May 31, 2019)

New:
Users can block known cryptominers and fingerprinters in the Custom settings of their Content Blocking preferences.
Keyboard accessibility has improved in the latest version of Firefox. Toolbar and toolbar overflow menu are both fully keyboard accessible: keyboard users can now access add-ons, the downloads panel, the overflow, Page actions and Firefox menus, and much more.
Firefox will now protect you against running older versions of the browser which can lead to data corruption and stability issues
Firefox is upgrading to the newer, higher performance, AV1 decoder known as ‘dav1d’
WebRender is gradually enabled by default on Windows 10 desktops with NVIDIA graphics cards
Mozilla’s highest performing JavaScript compiler now supports ARM64 Windows devices.
Enable FIDO U2F API, and permit registrations for Google Accounts
Some users will see experiments with an improved Pocket experience in Firefox Home with different layouts and more topical content.
Firefox 67 demonstrates improved performance thanks to a number of changes such as:
Lowering priority of setTimeout during page load
Delayed component initialization until after start up
Painting sooner during page load but less often
Suspending unused tabs
Private Browsing sees both usability and security improvements:
Save passwords in private browsing mode
Choose which extensions to exclude from private tabs
A myriad of new features help make Firefox easier to use:
We’ve added a toolbar menu for your Firefox Account to provide more transparency for when you are synced, sharing data across devices and with Firefox. Personalize the appearance of the menu with your own avatar
Tabs can now be pinned from the Page Actions menu in the address bar
Firefox will highlight useful features (like Pin Tabs) when users are most likely to benefit from them.
Easier access to your list of saved logins from the main menu and login autocomplete. Learn about all the ways you can manage your passwords in Firefox.
The Import Data from Another Browser feature is now also available from the File menu
Users will be able to run different Firefox installs side by side by default so that you can run the beta and release versions simultaneously
Fixed:
Various security fixes
Changed:
Firefox no longer supports handling webcal: links with 30boxes.com
Change to extensions in Private Windows: Any new extensions you add to the browser won’t work in Private Windows unless you allow this in the settings.
Users will no longer be able to upload and share screenshots through the Firefox Screenshots server. Users who want to keep existing screenshots need to export them before the server shuts down in the coming months.
Included Twemoji Mozilla font updated to support Emoji 11.0
Font and date adjustments to accommodate the new Reiwa era in Japan

New in Firefox 66.0.5 (May 8, 2019)

New in Firefox 66.0.2 (Apr 10, 2019)

New in Firefox 66.0.1 (Mar 25, 2019)

New in Firefox 66.0 (Mar 25, 2019)

New:
Firefox now prevents websites from automatically playing sound. You can add individual sites to an exceptions list or turn blocking off. To learn more about block autoplay, which will be rolled out gradually to all users, visit the Mozilla blog.
Smoother scrolling: Scroll anchoring keeps content from jumping as images and ads load at the top of the page
Redesigned certificate error pages help you better understand and resolve issues, including identification of certificate issuers for anti-virus software
Added basic support for macOS Touch Bar
Experimenting with an improved Pocket experience in New Tab with different layouts and more topical content
Improved performance and reduced crash rates by doubling web content loading processes from 4 to 8
Easier, passwordless security: Added support for Windows Hello on Windows 10, allowing you to use your face, fingerprint, or external security keys for website authentication
Enabled AV1 support on 32-bit Windows and MacOS. Firefox now supports the next-generation, royalty-free video compression technology called AV1. Read about Mozilla’s contribution to this new open standard.
Improved search experience:
Find a specific webpage faster when you have a lot of tabs open: You can now search within all of your open tabs from the tab overflow menu
Easier search via a redesigned new tab in Private Windows
Improved performance and better user experience for extensions:
Extensions now store their settings in a Firefox database, rather than individual JSON files, making every site you visit faster
A redesigned keyboard shortcuts section in about:addons makes it easier to view and adjust default shortcuts
Fixed:
The Dark and Light Firefox themes now override the system setting for title bar accent color on Windows 10
Linux users: Resolved an issue that caused Firefox to freeze when downloading files
Various security fixes
Changed:
System title bar is hidden by default to match Gnome guideline for Linux users
Developer:
DevTools Inspector is now fully usable when the Debugger is paused
Lowered priority of setTimeout and setInterval during page load to improve overall page load performance
Fixed: element is no longer special cased in event dispatch, per latest specifications

New in Firefox 65.0.2 (Mar 1, 2019)

New in Firefox 65.0.1 (Feb 13, 2019)

New in Firefox 66.0 Beta (Jan 30, 2019)

New in Firefox 65.0 (Jan 30, 2019)

New:
Enhanced tracking protection: Simplified content blocking settings give users standard, strict, and custom options to control online trackers. A redesigned content blocking section in the site information panel (viewed by expanding the small “i” icon in the address bar) shows what Firefox detects and blocks on each website you visit. To learn more about content blocking, visit the Mozilla Blog.
A better experience for multilingual users: An updated Language section in Preferences allows users to install multiple language packs and order language preferences for Firefox and websites, without having to download locale-specific versions.
Support for Handoff on macOS: Continue browsing across devices. Pick up where you left off with iOS (via Firefox or Safari) on Firefox on Mac.
A better video streaming experience for Windows users: Firefox now supports the next-generation, royalty-free video compression technology called AV1. Read about Mozilla’s contribution to this new open standard.
Improved performance and web compatibility, with support for the WebP image format: WebP brings the same image quality as existing formats at smaller file sizes, which saves bandwidth and speeds up page load.
Fixed:
Various security fixes.
Changed:
Enhanced security for macOS, Linux, and Android users via stronger stack smashing protection which is now enabled by default for all platforms. "Stack smashing" is a common security attack in which malicious actors corrupt or take control of a vulnerable program.
Firefox will now warn you when closing a window (regardless of whether you have automatic session restore enabled for restart).
Easier performance management: The revamped Task Manager page found at about:performance now reports memory usage for tabs and add-ons.
Improved the pop-up blocker to prevent multiple pop-up windows from being opened by websites at the same time.
Enterprise:
Firefox for Windows is now available with 32- and 64-bit MSI installers for easier enterprise deployments.
Developer:
Additional support for Flexbox: Launched a new Flexbox inspector tool that details Flexbox containers and helps debug Flex item sizes.
All CSS changes made in the Rules panel are now tracked in the new Changes tab.
Added support for the Storage Access API on desktop platforms.

New in Firefox 64.0.2 (Jan 10, 2019)

New in Firefox 64.0 (Dec 11, 2018)

New:
Better recommendations: You may see suggestions in regular browsing mode for new and relevant Firefox features, services, and extensions based on how you use the web (for US users only)
Enhanced tab management: You can now select multiple tabs from the tab bar and close, move, bookmark, or pin them quickly and easily
Easier performance management: The new Task Manager page found at about:performance lets you see how much energy each open tab consumes and provides access to close tabs to conserve power
Improved performance for Mac and Linux users, by enabling link time optimization (Clang LTO). (Clang LTO was enabled for Windows users in Firefox 63.)
More seamless sharing on Windows: Windows users can now share web pages using the native sharing experience. You can access Share in the Page Actions menu
Added option to remove add-ons using the context menu on their toolbar buttons
New for enterprise users: Updated the policy engine on macOS to allow using configuration profiles to customize Firefox for enterprise deployments
Fixed:
Various security fixes
Changed:
RSS feed preview and live bookmarks are available only via add-ons
TLS certificates issued by Symantec are no longer trusted by Firefox. Website operators are strongly encouraged to replace any remaining Symantec TLS certificates as soon as possible.
about:crashes has been redesigned to make it clear when a crash is being submitted to Mozilla, as well as being clear that removing crashes locally does not remove them from crash-stats.mozilla.com
The macOS keyboard shortcut to add "www" and ".com" to a URL is now ctrl-enter instead of [apple]-enter
Developer:
You may now overlay multiple CSS grids at the same time (up to 3) in the CSS Grid Inspector
The Web Console's command line now highlights JavaScript syntax
When hovering over elements in the Accessibility panel, the contrast ratio of text against background is now indicated
Added support for the new CSS scrollbar specification
WebVR is now available on macOS

New in Firefox 63.0.3 (Nov 16, 2018)

New in Firefox 64.0 Beta (Oct 23, 2018)

New in Firefox 63.0 (Oct 23, 2018)

New:
Added content blocking, a collection of Firefox settings that offer users greater control over technology that can track them around the web. In 63, users can opt to block third-party tracking cookies or block all trackers and create exceptions for trusted sites that don’t work correctly with content blocking enabled.
WebExtensions now run in their own process on Linux
Firefox now warns about having multiple windows and tabs open when quitting from the main menu
Firefox now recognizes the operating system accessibility setting for reducing animation
Added search shortcuts for Top Sites: Amazon and Google appear as Top Sites tiles on the Firefox Home (New Tab) page. When selected these tiles will change focus to the address bar to initiate a search. Currently in US only.
Performance improvements for macOS users:
Improved reactivity
Faster tab switching
WebGL power preferences allow non-performance-critical applications and applets to request the low-power GPU instead of the high-power GPU in multi-GPU systems
Fixed:
Resolved an issue that prevented the address bar from autofilling bookmarked URLs in certain cases
Changed:
In the Library, the Open in Sidebar feature for individual bookmarks was removed
The option to Never check for updates was removed from about:preferences. You can use the DisableAppUpdate enterprise policy as a substitute.
The Ctrl+Tab shortcut now displays thumbnail previews of your tabs and cycles through tabs in recently used order. This new default behavior is activated only in new profiles and can be changed in preferences.
Developer:
Refreshed visual style of Developer Tools menus to improve navigation and consistency
The Dev Tools accessibility inspector is now enabled by default. This tool surfaces information exposed to assistive technologies on the current page, allowing you to check what’s missing or otherwise needs attention.
Added support for Web Components custom elements and shadow DOM
The inspector now ships with a Font Editor that allows you to control non-variable as well as variable fonts

New in Firefox 62.0.3 (Oct 23, 2018)

New in Firefox 62.0.2 (Oct 23, 2018)

New in Firefox 62.0.3 (Oct 3, 2018)

New in Firefox 62.0.2 (Sep 22, 2018)

New in Firefox 63.0b3 Beta (Sep 5, 2018)

New in Firefox 62.0 (Sep 4, 2018)

New in Firefox 61.0.2 (Aug 8, 2018)

New in Firefox 61.0.1 (Jul 6, 2018)

New in Firefox 62.0 Beta 4 (Jun 29, 2018)

New in Firefox 60.0.2 (Jun 7, 2018)

New in Firefox 60.0.1 (May 17, 2018)

New in Firefox 59.0.2 (Mar 27, 2018)

New in Firefox 59.0.1 (Mar 26, 2018)

New in Firefox 60.0b6 Beta (Mar 22, 2018)

New in Firefox 59.0 (Mar 16, 2018)

NEW:
Drag-and-drop to rearrange Top Sites on the Firefox Home page, and customize new windows and tabs in other ways
Enhanced WebExtensions API including better support for decentralized protocols and the ability to dynamically register content scripts
Added support for W3C specs for pointer events and improved platform integration with added device support for mouse, pen, and touch screen pointer input
Added the Ecosia search engine as an option for German Firefox
Added the Qwant search engine as an option for French Firefox
Added settings in about:preferences to stop websites from asking to send notifications or access your device’s camera, microphone, and location, while still allowing trusted websites to use these features
Performance enhancements:
Faster load times for content on the Firefox Home page
Faster page load times by loading either from the networked cache or the cache on the user’s hard drive (Race Cache With Network)
Improved graphics rendering using Off-Main-Thread Painting (OMTP) for Mac users (OMTP for Windows was released in Firefox 58)
Added features for Firefox Screenshots:
Basic annotation lets the user draw on and highlight saved screenshots
Recropping to change the viewable area of saved screenshots
Improved Real-Time Communications (RTC) capabilities:
Implemented RTP Transceiver to give pages more fine grained control over calls
Implemented features to support large scale conferences
CHANGED:
Firefox Private Browsing Mode will remove path information from referrers to prevent cross-site tracking
VARIOUS SECURITY FIXES:
#CVE-2018-5127: Buffer overflow manipulating SVG animatedPathSegList:
#CVE-2018-5128: Use-after-free manipulating editor selection ranges:
#CVE-2018-5129: Out-of-bounds write with malformed IPC messages:
#CVE-2018-5130: Mismatched RTP payload type can trigger memory corruption:
#CVE-2018-5131: Fetch API improperly returns cached copies of no-store/no-cache resources
#CVE-2018-5132: WebExtension Find API can search privileged pages
#CVE-2018-5133: Value of the app.support.baseURL preference is not properly sanitized
#CVE-2018-5134: WebExtensions may use view-source: URLs to bypass content restrictions
#CVE-2018-5135: WebExtension browserAction can inject scripts into unintended contexts
#CVE-2018-5136: Same-origin policy violation with data: URL shared workers
#CVE-2018-5137: Script content can access legacy extension non-contentaccessible resources
#CVE-2018-5138: Android Custom Tab address spoofing through long domain names
#CVE-2018-5140: Moz-icon images accessible to web content through moz-icon: protocol
#CVE-2018-5141: DOS attack through notifications Push API
#CVE-2018-5142: Media Capture and Streams API permissions display incorrect origin with data: and blob: URLs
#CVE-2018-5143: Self-XSS pasting javascript: URL with embedded tab into addressbar
#CVE-2018-5126: Memory safety bugs fixed in Firefox 59
#CVE-2018-5125: Memory safety bugs fixed in Firefox 59 and Firefox ESR 52.7

New in Firefox 58.0.2 (Feb 8, 2018)

New in Firefox 59.0b3 Beta (Jan 24, 2018)

New in Firefox 58.0 (Jan 19, 2018)

New in Firefox 57.0.4 (Jan 5, 2018)

New in Firefox 57.0.3 (Dec 28, 2017)

New in Firefox 57.0.1 (Nov 30, 2017)

New in Firefox 58.0b3 Beta (Nov 14, 2017)

New in Firefox 57.0 (Nov 13, 2017)

New in Firefox 57.0 RC 3 (Nov 10, 2017)

New in Firefox 57.0b4 Beta (Sep 29, 2017)

New in Firefox 56.0 (Sep 28, 2017)

New in Firefox 55.0.3 (Aug 28, 2017)

New in Firefox 55.0.2 (Aug 18, 2017)

New in Firefox 55.0.1 (Aug 10, 2017)

New in Firefox 56.0b1 Beta (Aug 8, 2017)

New in Firefox 55.0 (Aug 7, 2017)

NEW:
Updated Sidebar for bookmarks, history, and synced tabs so it can appear at the right edge of the window as well as the left
Added support for stereo microphones with WebRTC
Simplified printing from Reader Mode
Updated Firefox for OSX and macOS to allow users to assign custom keyboard shortcuts to Firefox menu items via System Preferences
Browsing sessions with a high number of tabs are now restored in an instant
Make screenshots of webpages, and save them locally or upload them to the cloud. This feature will undergo A/B testing and will not be visible for some users.
Added Belarusian (be) locale
Added options that let users optimize recent performance improvements:
Setting to enable Hardware VP9 acceleration on Windows 10 Anniversary Edition for better battery life and lower CPU usage while watching videos
Setting to modify the number of concurrent content processes for faster page loading and more responsive tab switching
Improved address bar functionality:
Search with any installed one-click search engine directly from the address bar
Search suggestions appear by default
When entering a hostname (like pinterest.com) in the URL bar, Firefox resolves to the secure version of the site (https://www.pinterest.com) instead of the insecure version (http://www.pinterest.com) when possible
CHANGED:
Modernized application update UI to be less intrusive and more aligned with the rest of the browser. Only users who have not restarted their browser 8 days after downloading an update or users who opted out of automatic updates will see this change.
Firefox does not support downgrades, even though this may have worked in past versions. Users who install Firefox 55+ and later downgrade to an earlier version may experience issues with Firefox.
Made the Adobe Flash plugin click-to-activate by default and allowed only on http:// and https:// URL schemes. (This change will not be visible to all users immediately. For more information see the Firefox plugin roadmap)
DEVELOPER:
Sites that don’t use SSL can no longer access Geolocation APIs to determine a user’s physical location

New in Firefox 54.0.1 (Jun 30, 2017)

New in Firefox 55.0b4 Beta (Jun 24, 2017)

New in Firefox 55.0b2 Beta (Jun 17, 2017)

New in Firefox 55.0b1 Beta (Jun 15, 2017)

New in Firefox 54.0 (Jun 14, 2017)

New in Firefox 53.0.3 (May 20, 2017)

New in Firefox 54.0b7 Beta (May 12, 2017)

New in Firefox 53.0.2 (May 6, 2017)

New in Firefox 54.0b1 Beta (Apr 21, 2017)

New in Firefox 53.0 (Apr 19, 2017)

New in Firefox 52.0.2 (Mar 29, 2017)

New in Firefox 53.0b4 Beta (Mar 18, 2017)

New in Firefox 52.0.1 (Mar 18, 2017)

New in Firefox 53.0b1 Beta (Mar 9, 2017)

NEW:
Lightweight themes are now applied in private browsing windows
Reader Mode now displays estimated reading time for the page
Two new 'compact' themes available in Firefox, dark and light, based on the Firefox Developer Edition theme
CHANGED:
32-bit Mac OS X is no longer supported. Firefox is now a 64-bit only Mac OS X application
Updates for Mac OS X are smaller in size compared to updates for Firefox 52
Refresh of the media controls user interface
Shortened titles on tabs are faded out instead of using ellipsis for improved readability
Media playback on new tabs is blocked until the tab is visible
Permission notifications have a cleaner design and cannot be easily missed
CHANGES FOR WEB DEVELOPERS:
Developer Tools:
Added option to copy the full CSS path of an element (bug 1323700).
Devtools support for css-color-4 (bug 1310681).
markup view: add a visual hint between opening and closing tags of a collapsed node (bug 1323193).
HTML:
The dom.details_element.enabled pref — which controlled enabling/disabling and element support in Firefox — has now been removed from about:config. These elements (which were first enabled by default in Firefox 49) can no longer be disabled. See bug 1271549.
CSS - New features:
The mask-* longhand properties (see CSS Masks) are all supported and available by default (see bug 1251161).
Added caret-color property (bug 1063162).
Implemented the place-items/place-self/place-content shorthands (bug 1319958).
Added flow-root value to display property (bug 1322191).
-moz-tab-size now accepts values (bug 943918), and is now animatable (bug 1308110).
CSS - Other changes:
Removed -moz prefixed variant of :dir() pseudo-class (bug 1270406).
The -moz prefixed version of text-align-last got removed (bug 1276808).
Enable mask longhands on SVG elements (bug 1319667).
[css-grid] align-self/justify-self:stretch/normal doesn't work on grid items (bug 1316051).
Removed -moz prefixed variant of calc() method (bug 1331296).
clip-path: circle() with large reference box and percentage radius does not render correctly (bug 1324713.
When applying a text-transform value of uppercase to Greek text, the accent on the disjunctive eta (ή) is no longer removed (see bug 1322989).
appearance: none now works the same in Firefox (-moz-appearance: none;) as in other browsers (e.g. -webkit-appearance: none;) — see bug 418833.
The availability of the contents value of display was controlled through the layout.css.display-contents.enabled pref. In Firefox 53 this pref has been removed altogether, so the value will always be available and can no longer be disabled.
JavaScript:
ECMAScript 2015 semantics for the Function.name properties have been implemented. This includes inferred names on anonymous functions (var foo = function() {}) (bug 883377).
ECMAScript 2015 semantics for closing iterators have been implemented. This affects the for...of loop, for example (bug 1147371).
The Template Literal Revision proposal that lifts escape sequence restrictions on tagged template literals has been implemented (bug 1317375).
The non-standard ArrayBuffer.slice() method has been removed (but the standardized version ArrayBuffer.prototype.slice() is kept, see bug 1313112).
The non-standard String generics now present a deprecation warning in the console. Do not use them anymore, they will be removed in the future! (bug 1319926).
The static length property of TypedArray objects was changed from 3 to 0 as per ES2016 (bug 1317306).
SharedArrayBuffer can now be used in DataView objects (bug 1246597).
In earlier versions of the specification, SharedArrayBuffer objects needed to be explicitly transferred during structured cloning. In the new specification they aren't transferable objects anymore and thus must not be in the transfer list. The new behavior used to present a console warning only, but will now throw an error (bug 1302037).
The ArrayBuffer length is now limited to Number.MAX_SAFE_INTEGER (>= 2 ** 53) (bug 1255128).
The Error object (and other native error object prototypes like RangeError etc.) are now ordinary objects (Object.prototype.toString.call(Error.prototype) is now "[object Object]" instead of "[object Error]") (bug 1213341).
Events:
CSS Transitions: The transitionstart, transitionrun, and transitioncancel events have been implemented (see bug 1264125 and bug 1287983).
The MouseEvent.x and MouseEvent.y aliases of MouseEvent.clientX/MouseEvent.clientY have been implemented (see bug 424390).
The CompositionEvent constructor has been implemented (see bug 1002256).
The cancelBubble property, which was defined on UIEvent, is now defined on the Event interface instead. See bug 1298970 for more details.
The auxclick event and corresponding GlobalEventHandlers.onauxclick handler have been implemented (see bug 1304044).
The transitioncancel event is now fired after a transition is cancelled. See GlobalEventHandlers.ontransitioncancel for more details and an example (bug 1264125).
DOM:
The pathname and search HTMLHyperLinkElementUtils properties previously returned the wrong parts of the URL. For example, for a URL of http://z.com/x?a=true&b=false, pathname would return "/x?a=true&b=false" and search would return "", rather than "/x" and "?a=true&b=false" respectively. This has now been fixed (bug 1310483).
The URLSearchParams() constructor now accepts a USVString or sequence of USVStrings as an init object (bug 1330678).
The Selection.setBaseAndExtent() method of the Selection API is now implemented (see bug 1321623).
The "fakepath" addition to file type values has been implemented in Gecko, giving it parity with other browsers (see bug 1274596).
Node.getRootNode() has been implemented, replacing the deprecated Node.rootNode property (bug 1269155).
Own properties of Plugin and PluginArray objects are no longer enumerable (bug 1270366).
Named properties of MimeTypeArray objects are no longer enumerable (bug 1270364).
The Permissions API now has a new permission name available — persistent-storage — as used when making a Permissions.query() (see bug 1270038). This allows an origin to use a persistent box (i.e persistent storage) for its storage, as per the Storage API.
Workers:
The Network Information API is now available in workers (see bug 1323172).
Server-sent events can now be used from workers (see bug 1267903).
Service Workers:
ExtendableEvent.waitUntil() can now be called asynchronously (see bug 1263304).
WebGL:
The WEBGL_compressed_texture_astc WebGL extension has been implemented (bug 1250077).
Audio/Video/Media:
The HTMLMediaElement.play() method, used to begin playback of media in any media element, now returns a Promise which is fulfilled when playback begins and is rejected if an error occurs.
The AudioScheduledSourceNode interface has been added and the AudioBufferSourceNode, ConstantSourceNode, and OscillatorNode interfaces are now based on it.
HTTP:
Gecko now has a pref available in about:config to allow users to set their default Referrer-Policy — network.http.referer.userControlPolicy.
SVG:
Partly implemented SVGGeometryElement interface (bug 1239100).
Removals:
The Wifi information API, Speaker Manager API, and Tethering API, and Settings API have been removed from the platform (see bug 1313788, bug 1317853, bug 1313789, and bug 1313155 respectively).
BUG FIXES:
Bug 1343938 - Fix new installs erroneously not prompting to change the default browser setting.
Bug 1343850 - Fix PlacesProvider.jsm undefined variable (aLastKnownTitle vs. aTitle).
Bug 1341097 - Part 4: Misc. small optimizations.
Bug 1341097 - Part 3: Don't dispatch oodles of titlechanged notifications for new history entries.
Bug 1341097 - Part 2: Allow turning off notifications for individual inserted results when calling updatePlaces
Bug 1341097 - Part 1: Group frecency notifications from history notifications.
Bug 1300376 - Update zoom indicator when moving a browser to another window.
Bug 1319403 - Modified nsCookieService::FindStaleCookie() and test cases.
Bug 1341149 - Implement ImageLayerClipState::ctor
Bug 1339852 - Fix a content canvas crash caused by losing IPC during a GPU process restart.
Bug 1344074 - Make sure ParamTraits::Read use the correct type.
Bug 1341691 - Improve handling of touch events when dismissing popups.
Bug 1344102 - Add a telemetry for xml:base on styled element.
Bug 1343446 - NativeKey::GetFollowingCharMessage() should ignore found message if PeekMessage(PM_REMOVE) retrieves different char message but the found odd char message was odd.

New in Firefox 52.0 (Mar 7, 2017)

NEW:
Added support for WebAssembly, an emerging standard that brings near-native performance to Web-based games, apps, and software libraries without the use of plugins.
Implemented the Strict Secure Cookies specification which forbids insecure HTTP sites from setting cookies with the "secure" attribute. In some cases, this will prevent an insecure site from setting a cookie with the same name as an existing "secure" cookie from the same base domain.
Added user warnings for non-secure HTTP pages with logins. Firefox now displays a “This connection is not secure” message when users click into the username and password fields on pages that don’t use HTTPS.
Enabled multi-process Firefox for Windows users with touch screens
Enhanced Sync to allow users to send and open tabs from one device to another.
FIXED:
Various security fixes
Improved text input for third-party keyboard layouts on Windows. This will address some keyboard layouts that:
have chained dead keys
input two or more characters with a non-printable key or a dead key sequence
input a character even when a dead key sequence failed to compose a character
CHANGED:
Removed support for Netscape Plugin API (NPAPI) plugins other than Flash. Silverlight, Java, Acrobat and the like are no longer supported.
Display (but allow users to override) an “Untrusted Connection” error when encountering SHA-1 certificates that chain up to a root certificate included in Mozilla’s CA Certificate Program. (Note: Firefox continues to permit SHA-1 certificates that chain to manually imported root certificates.) Read more about the Mozilla Security Team’s plans to deprecate SHA-1
Removed Battery Status API to reduce fingerprinting of users by trackers
When not using Direct2D on Windows, Skia is used for content rendering
Migrated Firefox users on Windows XP and Windows Vista operating systems to the extended support release (ESR) version of Firefox.
Improved experience for downloads:
Notification in the toolbar when a download fails
Quick access to five most recent downloads rather than three
Larger buttons for canceling and restarting downloads
DEVELOPER:
Enabled CSS Grid Layout, opening up a world of new possibilities for graphic design
Improved security for screen sharing, which now shows a preview and no longer requires a whitelisted domain
Redesigned Responsive Design Mode to include device selection, network throttling, and more

New in Firefox 51.0.1 (Jan 27, 2017)

New in Firefox 52.0b1 Beta (Jan 26, 2017)

New in Firefox 51.0 (Jan 25, 2017)

New in Firefox 50.0.2 (Dec 1, 2016)

New in Firefox 50.0.1 (Nov 29, 2016)

New in Firefox 51.0b3 Beta (Nov 29, 2016)

New in Firefox 52.0a2 Developer (Nov 22, 2016)

New in Firefox 51.0b1 Beta (Nov 16, 2016)

New in Firefox 50.0 (Nov 15, 2016)

New in Firefox 50.0b10 Beta (Oct 25, 2016)

New in Firefox 50.0b9 Beta (Oct 21, 2016)

New in Firefox 49.0.2 (Oct 21, 2016)

New in Firefox 49.0.2 RC 1 (Oct 19, 2016)

New in Firefox 50.0b7 Beta (Oct 18, 2016)

New in Firefox 50.0b4 Beta (Oct 4, 2016)

New in Firefox 51.0a2 Developer (Sep 27, 2016)

New in Firefox 50.0b2 Beta (Sep 27, 2016)

New in Firefox 49.0.1 (Sep 23, 2016)

New in Firefox 50.0b1 Beta (Sep 21, 2016)

New in Firefox 49.0 (Sep 19, 2016)

New in Firefox 49.0b8 Beta (Aug 30, 2016)

New in Firefox 49.0b7 Beta (Aug 30, 2016)

New in Firefox 49.0b6 Beta (Aug 26, 2016)

New in Firefox 49.0b5 Beta (Aug 26, 2016)

New in Firefox 48.0.1 (Aug 19, 2016)

New in Firefox 49.0b4 Beta (Aug 16, 2016)

New in Firefox 49.0b3 Beta (Aug 16, 2016)

New in Firefox 49.0b2 Beta (Aug 12, 2016)

New in Firefox 50.0a2 Developer (Aug 11, 2016)

New in Firefox 49.0b1 Beta (Aug 3, 2016)

New in Firefox 48.0 (Aug 2, 2016)

NEW:
Roar for moar protection against harmful downloads! We've got your back
Process separation (e10s) is enabled for some of you. Like it? Let us know and we'll roll it out to more.
Add-ons that have not been verified and signed by Mozilla will not load
Searching for something already in your bookmarks or open tabs? We added super smart icons to let you know
The media parser has been redeveloped using the Rust programming language
WebRTC embetterments:
Delay-agnostic AEC enabled
Full duplex for GNU/Linux enabled
ICE Restart & Update is supported
Cloning of MediaStream and MediaStreamTrack is now supported
FIXED:
Heyo, Jabra & Logitech C920 webcam users. We fixed those pesky WebRTC bugs causing frequency distortions. Buh-bye, squeaky voice!
Improved step debugging on last line of functions
CHANGED:
So long to support for 10.6, 10.7 and 10.8. Now we can focus on where most Mac users are: 10.9. Don't forget to upgrade!
DEVELOPER:
WebExtensions support is now considered as stable
Want to move absolute & fixed positioned elements? (Who doesn't, right?) Now you can with our geometry editor.
The memory tool now has a tree map view for your debugging pleasure. It's a little bit of "boo" and a whole lot of "ya."
We're putting the spotlight on the background. Now you can debug WebExtensions background content scripts and background pages
Content Security Policy (CSP) is now enforced for WebExtensions. (Who's down with CSP?)
Old and busted: Error Console. New hotness: Browser Console for your debugging pleasure.
Add-on development just got easier because you can reload them from about:debugging — because we're all about debugging.
This theme is hot, hot, hot! Say hi to the Firebug theme for Developer Tools.
Expand network requests from the console panel to view request details in line, so you can see things in context
Workers can now use the Web Crypto API
SECURITY FIXES:
2016-84 Information disclosure through Resource Timing API during page navigation
2016-83 Spoofing attack through text injection into internal error pages
2016-82 Addressbar spoofing with right-to-left characters on Firefox for Android
2016-81 Information disclosure and local file manipulation through drag and drop
2016-80 Same-origin policy violation using local HTML file and saved shortcut file
2016-79 Use-after-free when applying SVG effects
2016-78 Type confusion in display transformation
2016-77 Buffer overflow in ClearKey Content Decryption Module (CDM) during video playback
2016-76 Scripts on marquee tag can execute in sandboxed iframes
2016-75 Integer overflow in WebSockets during data buffering
2016-74 Form input type change from password to text can store plain text password in session restore file
2016-73 Use-after-free in service workers with nested sync events
2016-72 Use-after-free in DTLS during WebRTC session shutdown
2016-71 Crash in incremental garbage collection in JavaScript
2016-70 Use-after-free when using alt key and toplevel menus
2016-69 Arbitrary file manipulation by local user through Mozilla updater and callback application path parameter
2016-68 Out-of-bounds read during XML parsing in Expat library
2016-67 Stack underflow during 2D graphics rendering
2016-66 Location bar spoofing via data URLs with malformed/invalid mediatypes
2016-65 Cairo rendering crash due to memory allocation issue with FFmpeg 0.10
2016-64 Buffer overflow rendering SVG with bidirectional content
2016-63 Favicon network connection can persist when page is closed
2016-62 Miscellaneous memory safety hazards (rv:48.0 / rv:45.3)

New in Firefox 48.0b10 Beta (Jul 25, 2016)

New in Firefox 48.0b9 Beta (Jul 19, 2016)

New in Firefox 48.0b6 Beta (Jul 8, 2016)

New in Firefox 48.0b5 Beta (Jul 1, 2016)

New in Firefox 47.0.1 (Jun 28, 2016)

New in Firefox 48.0b4 Beta (Jun 28, 2016)

New in Firefox 48.0b3 Beta (Jun 24, 2016)

New in Firefox 48.0b2 Beta (Jun 22, 2016)

New in Firefox 49.0a2 Developer (Jun 11, 2016)

New in Firefox 48.0b1 Beta (Jun 8, 2016)

New in Firefox 47.0 RC 2 (Jun 3, 2016)

New in Firefox 47.0b8 Beta (May 24, 2016)

New in Firefox 47.0b6 Beta (May 17, 2016)

New in Firefox 47.0b5 Beta (May 13, 2016)

Bug 1216658 - Ignore Gt3 dark themes and use light theme's color scheme for native widgets
Bug 1271032 - Make getPref Unicode-aware
Bug 1271280 - Places shutdown blockers have wrong names and are not properly reporting state
Bug 1247137 - Show spinner if switching away from browser that goes away immediately.
Bug 1269365 - Part 3 - Use infallible array allocation in implementSpecialArrayPickling. As with part 2, this will turn some allocation failures during
deserialization from IPC FatalError crashes into OOM crashes.
Bug 1269365 - Part 2 - Make ParamTraits::Read use infallible allocation. This will turn allocation failures during deserialization from IPC
FatalError crashes into OOM crashes.
Bug 1269365 - Part 1 - Swap fallible and infallible TArray ParamTraits. This should not change the behavior, because fallible_t is passed to
the array methods. Rename from InfallibleTArray to nsTArray, because that is more usual. Remove unnecessary spaces from some template definitions.
Bug 1271037 - Fix numOperands of RRegExpMatcher, and RRegExpTester.
Backed out 6 changesets (bug 1268749, bug 1268750) until a fix can be landed for the rc2 permafail a=backout
Bug 1255336: Copy DEVMODE details back to print settings in GetDataFromPrinter
Bug 1243538: P6. Adjust gonk decoder to allow different decoding size from metadata. Additionally handle bug 1154162, and fix aspect ratio. The display size were used for the picture size which would be wrong if any aspect ratio was set.
Bug 1243538: P5. Adjust wmf decoder to allow different decoding size from metadata.
Bug 1243538: P4. Adjust ffvpx decoder to allow different decoding size from metadata.
Bug 1243538: P3. Adjust libvpx decoder to allow different decoding size from metadata
Bug 1243538: P2. Add convenience VideoInfo::ScaledImageRect.
Bug 1243538: P1. Make MediaInfo::mImage an nsIntSize again and introduce a mImageRect member.
Bug 1268749 part 6 - Add test for behavior when unprefixed api is disabled.
Bug 1268749 part 5 - Avoid dispatching unprefixed fullscreen events to content if unprefixed API is disabled.
Bug 1268750 part 4 - Hide unprefixed Fullscreen API from content when disabled.

New in Firefox 47.0b4 Beta (May 13, 2016)

New in Firefox 47.0b3 Beta (May 6, 2016)

New in Firefox 46.0.1 (May 3, 2016)

New in Firefox 47.0b2 Beta (May 3, 2016)

New in Firefox 47.0b1 Beta (Apr 27, 2016)

New in Firefox 46.0 (Apr 25, 2016)

New in Firefox 46.0b10 Beta (Apr 12, 2016)

New in Firefox 45.0.2 (Apr 11, 2016)

New in Firefox 45.0.1 (Apr 11, 2016)

New in Firefox 46.0b8 Beta (Apr 5, 2016)

New in Firefox 46.0b7 Beta (Apr 2, 2016)

New in Firefox 46.0b4 Beta (Mar 22, 2016)

New in Firefox 46.0b2 Beta (Mar 17, 2016)

New in Firefox 46.0b1 Beta (Mar 10, 2016)

New in Firefox 45.0 (Mar 8, 2016)

New:
Instant browser tab sharing through Hello
Tabs synced via Firefox Accounts from other devices are now shown in dropdown area of Awesome Bar when searching
Synced Tabs button in button bar
Introduce a new preference (network.dns.blockDotOnion) to allow blocking .onion at the DNS level
Guarani [gn] locale added
Fixed:
URLs containing a Unicode-format Internationalized Domain Name (IDN) are now properly redirected
Various security fixes
Changed:
Tab Groups (Panorama) feature removed
Developer:
Ability to filter snapshot output in memory tool
Fine tune animations by changing the playback rate of animations in the animation-inspector's timeline
DOMContentLoaded and load events shown in the network monitor timeline
Added Negative url filtering for the network monitor
Support for diffing heap snapshots added to the memory tool
Inspector search now matches results from all content in the page, including subframes
List of animated properties and keyframes is now displayed when clicking on an animation in the animation-inspector’s timeline
HTML5:
Push API support, part of Progressive Web Applications
Support delivery of a Content Security Policy (CSP) via a meta tag
Web Speech synthesis API
ES6 Classes
Security fixes:
2016-37 Font vulnerabilities in the Graphite 2 library
2016-36 Use-after-free during processing of DER encoded keys in NSS
2016-35 Buffer overflow during ASN.1 decoding in NSS
2016-34 Out-of-bounds read in HTML parser following a failed allocation
2016-33 Use-after-free in GetStaticInstance in WebRTC
2016-32 WebRTC and LibVPX vulnerabilities found through code inspection
2016-31 Memory corruption with malicious NPAPI plugin
2016-30 Buffer overflow in Brotli decompression
2016-29 Same-origin policy violation using perfomance.getEntries and history navigation with session restore
2016-28 Addressbar spoofing though history navigation and Location protocol property
2016-27 Use-after-free during XML transformations
2016-26 Memory corruption when modifying a file being read by FileReader
2016-25 Use-after-free when using multiple WebRTC data channels
2016-24 Use-after-free in SetBody
2016-23 Use-after-free in HTML5 string parser
2016-22 Service Worker Manager out-of-bounds read in Service Worker Manager
2016-21 Displayed page address can be overridden
2016-20 Memory leak in libstagefright when deleting an array during MP4 processing
2016-18 CSP reports fail to strip location information for embedded iframe pages
2016-17 Local file overwriting and potential privilege escalation through CSP reports
2016-16 Miscellaneous memory safety hazards (rv:45.0 / rv:38.7)

New in Firefox 45.0 RC 1 (Mar 1, 2016)

New in Firefox 45.0b10 Beta (Feb 26, 2016)

New in Firefox 45.0b9 Beta (Feb 24, 2016)

New in Firefox 45.0b8 Beta (Feb 22, 2016)

New in Firefox 45.0b7 Beta (Feb 19, 2016)

New in Firefox 45.0b6 Beta (Feb 16, 2016)

New in Firefox 45.0b5 Beta (Feb 12, 2016)

New in Firefox 44.0.2 (Feb 11, 2016)

New in Firefox 45.0b4 Beta (Feb 9, 2016)

New in Firefox 44.0.1 (Feb 8, 2016)

New in Firefox 45.0b3 Beta (Feb 5, 2016)

Kevin Brosnan - Bug 1235202 - Disable dynamic tile size for Firefox for Android a=sylvestre
Bug 1204784: Do not shut the main thread down before all outstanding asynchronous thread shutdowns complete. r=froydnj, a=sylvestre
Bug 1231554 - Disable the dynamic toolbar on Galaxy Note devices running Android 4.1.2. r=sebastian a=sylvestre
Bug 1243507 - Reimplement non-Unicode clipboard formats as bug 943294 broke drag and drop between some Unicode-unaware apps. r=jimm, a=sylvestre
Bug 1227548 - Check the result of MakeCurrent in ReadBuffer and DrawBuffer destructors - r=jgilbert, a=sylvestre
Bug 1244505 - Allow spaces in cookie names. r=mcmanus, a=sylvestre
Bug 1244076 - Fix a crash in nsDocShell::IssueWarning by null-checking mContentViewer; r=bzbarsky, a=sylvestre
Bug 1240892 - Disable default-app hash storage. r=dolske, a=sylvestre
Bug 1242777 - Expose child process hang stats to Javascript. r=chutten, a=sylvestre:
What it does:
Adds a new function, TelemetrySession.getChildThreadHangs(), which returns a promise resolving to an array of threadHangStats [1], one per process.
Note that processes that spawn or die while the function's promise is created but not resolved may be excluded from the final result.
How we do this:
Parent sends a MESSAGE_TELEMETRY_GET_CHILD_PAYLOAD message to each child, promising the results of these messages.
Child processes respond to parent with a MESSAGE_TELEMETRY_THREAD_HANGS, which contains BHR stats in the payload.
Parent combines all the child responses together and resolves the promise.
Plus a bunch of synchronization stuff and handling of edge cases since the number of child processes can change at any time.
Also, there is a 200ms timeout since we can't handle all of these cases. Specifically, when a child dies without responding, after all other child processes have responded.
Why we do this:
We can technically get thread hang stats by retrieving Telemetry pings (see requestChildPayloads() in TelemetrySession for details), but this is very slow and can only be done for one process at a time.
TelemetrySession is responsible for various Telemetry IPC-related tasks, and so is a natural place to expose this function (i.e., the function blends in well with the rest of the API).
Statuser [2] uses this for quickly obtaining child process BHR stats. This allows us to get realtime hang monitoring for child processes
Bug 1204784 - Handle cases in nsThreadPool where Gecko doesn't own the thread that we're running on. r=froydnj, a=sylvestre
Bug 1220272 - Fix signalling in HTTP cache test code suspender. r=michal, a=sylvestre
Bug 913822 - Shutdown I/O time limit for HTTP cache. r=michal, a=sylvestre
Bug 1244693 - On Beta/Release channels, allow OpenType Layout tables (GDEF/GPOS/GSUB) to pass through OTS unchecked, relying on harfbuzz to handle them safely. r=jdaggett a=sledru
Bug 1243881 - patch 2 - unship performance.translateTime, r=bz, a=sylvestre
Bug 1243881 - patch 1 - unship performance.translateTime, r=bz, a=sylvestre

New in Firefox 45.0b2 Beta (Feb 2, 2016)

New in Firefox 45.0b1 Beta (Jan 29, 2016)

New in Firefox 46.0a2 Developer (Jan 29, 2016)

New in Firefox 45.0b1 Beta (Jan 28, 2016)

New in Firefox 44.0 (Jan 27, 2016)

New:
Improved warning pages for certificate errors and untrusted connections
Enable H.264 if system decoder is available
Enable WebM/VP9 video support on systems that don't support MP4/H.264
In the animation-inspector timeline, lightning bolt icon next to animations running on the compositor thread
Support the brotli compression format via HTTPS content-encoding
Screenshot commands allow user choice of pixel ratio in Developer Tools
Fixed:
Windows XP and Vista screensaver doesn't disable when watching videos (Bug 1193610)
Various security fixes
Changed:
To support unicode-range descriptor for webfonts, font matching under Linux now uses the same font matching code as other platforms
Use a SHA-256 signing certificate for Windows builds, to meet new signing requirements
Firefox has removed support for the RC4 decipher
Firefox will no longer trust the Equifax Secure Certificate Authority 1024-bit root certificate or the UTN - DATACorp SGC to validate secure website certificates
Stricter validation of web fonts
On-screen keyboard support temporarily turned off for Windows 8 and Windows 8.1
Developer:
Right click on a logged object in the console to store it as a global variable on the page
New memory tool for inspecting the memory heap
Service Workers API
Built-in JSON reader to intuitively view, search, copy and save data without extensions
Jump to function definitions in the debugger with Cmd-Click
WebSocket Debugging API and add-on
The rule view now displays styles using their authored text, and edits in the rule view are now linked to the style editor
Visual tools for Animation:
View/Edit CSS animation keyframe rules directly in the inspector
Visually modify the cubic-bezier curve that drives the way animations progress through time
Discover and scrub through all CSS animations and transitions playing on the page
Visual tools for Layout and Styles:
Display rulers along the viewport to verify size and position and use the measurement tool to easily detect spacing and alignment problems
Use CSS filters to preview and create real-time effects like drop-shadows, sepia, etc.
Security fixes:
2016-12 Lightweight themes on Firefox for Android do not verify a secure connection
2016-11 Application Reputation service disabled in Firefox 43
2016-10 Unsafe memory manipulation found through code inspection
2016-09 Addressbar spoofing attacks
2016-08 Delay following click events in file download dialog too short on OS X
2016-07 Errors in mp_div and mp_exptmod cryptographic functions in NSS
2016-06 Missing delay following user click events in protocol handler dialog
2016-05 Addressbar spoofing through stored data url shortcuts on Firefox for Android
2016-04 Firefox allows for control characters to be set in cookie names
2016-03 Buffer overflow in WebGL after out of memory allocation
2016-02 Out of Memory crash when parsing GIF format images
2016-01 Miscellaneous memory safety hazards (rv:44.0 / rv:38.6)

New in Firefox 44.0 RC 3 (Jan 25, 2016)

New in Firefox 44.0b9 Beta (Jan 15, 2016)

New in Firefox 44.0b8 Beta (Jan 12, 2016)

New in Firefox 44.0b7 Beta (Jan 8, 2016)

New in Firefox 43.0.4 (Jan 6, 2016)

New in Firefox 44.0b6 Beta (Jan 5, 2016)

New in Firefox 44.0b4 Beta (Dec 29, 2015)

New in Firefox 43.0.3 (Dec 28, 2015)

New in Firefox 43.0.2 RC 1 (Dec 22, 2015)

New in Firefox 44.0b2 Beta (Dec 22, 2015)

New in Firefox 43.0 (Dec 14, 2015)

New in Firefox 43.0 RC 1 (Dec 8, 2015)

New in Firefox 43.0b9 Beta (Dec 4, 2015)

New in Firefox 43.0b8 Beta (Dec 2, 2015)

New in Firefox 43.0b7 Beta (Nov 27, 2015)

New in Firefox 43.0b6 Beta (Nov 24, 2015)

New in Firefox 43.0b5 Beta (Nov 20, 2015)

New in Firefox 43.0b4 Beta (Nov 17, 2015)

New in Firefox 43.0b3 Beta (Nov 13, 2015)

New in Firefox 43.0b2 Beta (Nov 10, 2015)

Backed out 4 changesets (bug 1210852, bug 1103188, bug 1070216) for various crashes with mediamanager.cpp assertions a=backout
Backed out changeset 3705005d2190 (bug 1070216)
Backed out changeset c458ad434a12 (bug 1210852)
Backed out changeset 1babaebeccc6 (bug 1103188)
Backed out changeset b199ea9f265c (bug 1103188)
Bug 1070216 - Properly manage lifetime of allocated CaptureDevices. r=jib a=lizzard
We currently avoid Deallocating a CaptureDevice used for multiple gUMStreams when one of them calls Deallocate() by keeping track of how many called Start().
The normal lifetime sequence however, is:
Allocate()
Start()
Stop()
Deallocate()
This patches fixes the lifetime management by keeping track of how many users of the CaptureDevice called Allocate().
Bug 1210852 - do SelectSettings of device capabilities on media thread. a=lizzard
Bug 1103188 - Keep track of stopped tracks in gUM stream listener. r=jib a=lizzard
This is needed to avoid something like:
[old stream] stop track 1 -> deallocate MediaDevice for track 1
[new stream] gUM() -> allocate MediaDevice for track 1
[old stream] stop stream -> deallocate MediaDevice for track 1
[new stream] gUM() -> start MediaDevice for track 1 (oops, MediaDevice was no more!)
Bug 1103188 - Keep track of capture stop only in gUM stream listener. r=jib a=lizzard
Bug 1199131 - Crash when click on a SELECT wich has at least 1 OPTION with background-attachment:fixed and a background. r=mstange, a=lizzard
Bug 1156238. At minimum always use the root reference frame as the "stop at" ancestor when finding the animated geometry root.
Bug 1156238. Skip setting async scroll clips if we aren't painting to the window because they are useless then. r=mstange
Displayports only get acted upon when painting to the window, and the async scroll clips only get computed when we use a displayport.
In addition we change an assert because if we are painting to the window then our root reference frame is either a root frame, or a popup frame. In either case we should not be able to get to out of flows outside of the frame subtree rooted at the root reference frame by following placeholders.
Bug 1219134: P4. Properly assign the decoded sample duration. r=edwin a=sylvestre
We default to the previous logic if for some unlikely condition we couldn't find the frame's duration (using the last input frame's duration)
Bug 1219134: P3. Properly set the keyframe flag. r=edwin a=sylvestre
We were incorrectly setting the keyframe flag of the last input sample rather than of the decoded one.
Bug 1219134: P1. Fix pts calculation in FFmpeg video decoder. r=edwin a=sylvestre
This is the primary reason why we got no pts returned (pts were set to 0) when using early version of LibAV. Apparently you are expected to set the pts when allocating the buffer of a frame.
This is undocumented, but both LibAV and FFmpeg do so internally. So do the same.
Bug 1220037 - test convolution. r=padenot, a=sylvestre
This is in the mochitest suite so that Android and B2G tests can run it, but designed so that it can be moved to web-platform-tests when they run on all platforms.
Bug 1220037 - pack and unpack Nyquist for MOZ_LIBAV_FFT. r=padenot, a=sylvestre
BufferComplexMultiply knows nothing about this format and so ends up corrupting the DC coefficient if packed Nyquists are multiplied.
Bug 1211708 - Allow themes to specify XBL bindings even in unprivileged documents. r=sicking, a=sylvestre
Bug 1219833 - Respect composition underline color; r=masayuki, a=sylvestre
nsTextFrame didn't use the composition underline color if the composition didn't have a foreground color defined. This patch makes it use the underline color if foreground color is not defined.
Bug 1219833 - Respect composition underline color; r=masayuki, a=sylvestre
nsTextFrame didn't use the composition underline color if the composition didn't have a foreground color defined. This patch makes it use the underline color if foreground color is not defined.

New in Firefox 43.0b1 Beta (Nov 4, 2015)

New in Firefox 42.0 (Nov 2, 2015)

New in Firefox 42.0b9 Beta (Oct 23, 2015)

New in Firefox 42.0b8 Beta (Oct 20, 2015)

New in Firefox 42.0b7 Beta (Oct 16, 2015)

New in Firefox 41.0.2 (Oct 15, 2015)

New in Firefox 42.0b6 Beta (Oct 13, 2015)

New in Firefox 42.0b5 Beta (Oct 9, 2015)

New in Firefox 41.0.1 (Oct 1, 2015)

New in Firefox 41.0 (Sep 23, 2015)

New in Firefox 41.0b9 Beta (Sep 11, 2015)

Bug 1185960 - add workaround for bug 1202618. r=gijs a=sylvestre
Bug 1185960 followup for copy/paste fail: add line that was missed on OS X. a=ritu
Bug 1194568 - Renaming live bookmark while adding it renames the wrong one.
Bug 1193621 - Can't change tag name in library. r=ttaubert a=ritu
Bug 1200698: Rename async plugin init pref; r=bsmedberg a=ritu
Bug 1201793 - return correct result even after bailout a=ritu r=nbp
Bug 1202421 - Rename the network.auth.allow-subresource-auth pref. r=michal
Bug 1202844, make nsXBLService::GetBinding deal with shutting down during binding
Bug 1200148 - Sanity check header lengths in Vorbis CodecData. r=derf a=ritu
Bug 1194856 - Load noscript.css and noframes.css from data: URLs in release builds. Bug 1197943: Turn off MITIGATION_STRICT_HANDLE_CHECKS for NPAPI process sandbox for causing hangs.
Bug 1160295: Part 2, beta patch. r=bas, a=ritu
Bug 1200004 - Fix IDB permission handling around navigated windows. r=baku a=ritu
Bug 1203294 - Disable signon.rememberSignons.visibilityToggle. r=dolske a=ritu
Bug 1203584: Turn off add-on signing requirements. a=ritu
Bug 1200027: Fix installing add-ons from the AMO discovery pane in the add-ons manager. r=dveditz a=ritu
Bug 1165599 - Restore basic external view source. r=jsantell a=ritu
Backed out changeset da0ee59da1ba (bug 1200027) for browser-chrome bustages
Bug 1203220: Skip browser_pluginCrashReportNonDeterminism.js on beta; r=jimm a=testonly
Backed out changeset 7fee86b95a6b (bug 1160447) a=backout
Bug 1197152: Remove all wake adjustments to Timers r=froydnj a=ritu
Bug 1201535 - Always enable view source tabs for tests. r=me a=ritu
Bug 1201535 - Disable view source tabs for Beta / Release. r=bz ba=ritu
Bug 1044077 - Tweak some jemalloc constants. r=glandium a=ritu
Bug 1194842 - Fix the width calculation of the textbox for editable XUL tree cells in RTL mode; r=jaws a=ritu
Bug 1200027: Fix installing add-ons from the AMO discovery pane in the add-ons manager. r=dveditz a=ritu
Bug 1192159: Do not forget about the transform when not using an active target. r=jrmuizel a=ritu
Bug 1190735 - Remove nsITimer.TYPE_REPEATING_PRECISE (for beta). r=froydnj a=ritu
Backed out 7218018d3945 (bug 1193547) for causing intel crashes (bug 1202700).
Backed out 65d63fc8b1de (bug 1196411) for causing intel crashes (bug 1202700).
Bug 1199997 - Part.1 - nsTextStore::QueryInsert() should return specified range if the TIP is one of buggy Chinese TIPs of Microsoft r=VYV03354, a=ritu
Bug 1199997 - Part.0 - Add methods to check whether the active TIP is Chinese TIP which deosn't show candidate window in e10s mode. r=emk, a=ritu
Bug 1182046 - undeclared variables in nsLivemarkService.js. r=ttaubert, a=ritu
Bug 1202287 - Remove end padding on URL bar. r=ntim a=ritu
Bug 1194488 - Whitelist specific plugins for async init. r=jimm, a=ritu
Bug 1194784: Sideloaded add-ons without full signing don't display an appropriate warning in the add-ons manager. r=dao a=ritu
Remove the ability to force directwrite on. (bug 1193641, r=milan, a=ritu)

New in Firefox 41.0b8 Beta (Sep 8, 2015)

New in Firefox 41.0b7 Beta (Sep 5, 2015)

New in Firefox 41.0b6 Beta (Sep 1, 2015)

New in Firefox 41.0b5 Beta (Aug 28, 2015)

New in Firefox 40.0.3 (Aug 27, 2015)

New in Firefox 40.0.3 RC 1 (Aug 26, 2015)

New in Firefox 41.0b4 Beta (Aug 25, 2015)

New in Firefox 41.0b3 Beta (Aug 21, 2015)

Bug 1088637 - check we get the right transition event, r=Enn a=ritu
Bug 1181595 - MessagePortChild should check if the MessagePort is still alive before dispatching messages, r=smaug a=ritu
Bug 1189030 - Add pref "media.peerconnection.ice.relay_only" (default=false) r=jesup a=ritu
Bug 1160447: Crash when content policy rejects loads to netflix domains for diagnostic purposes. r=jst,cpearce a=ritu
Bug 1160447 - Only crash once per XHR failure to nflxvideo.net. r=khuey
Bug 1190238: P3. Do not loop calling MediaResource::Read or ReadAt, let MediaResourceIndex do it for us. r=cpearce, a=ritu
This allows to remove a fair amount of duplicated logic.
Most of it is in obsoleted code though.
Bug 1190238: P2. Have MediaResourceIndex::ReadAt() only stop early when reaching EOS or error. r=cpearce, a=ritu
MediaResource::ReadAt() requires to loop several times to ensure that all data has been read as it may return less data than requested.
This will allow to remove the handling of this particular shortcoming in MediaResources' users.
Bug 1190238: P1. Remove MediaResource::Read/Seek. r=cpearce, a=ritu
This functionality is now replaced with a dedicated new MediaResourceIndex class.
This allows for concurrent Read/Seek use of the MediaResource without having side effects.
Bug 1195291 - update talos.json to pick up latest tps, cleanup, and summarization code. r=parkouss, a=test-only
Bug 1195098. Null check for blurred source surface. r=mstange a=ritu
Bug 1192686 - fix css warning for download button variables, r=dao a=ritu
Bug 1194627 - Change group when sweeping preliminary objects to avoid leaking their slots. r=bhackett a=ritu
Bug 1194265 - Some default search engines should only be visible in specific countries, r=Mossop. a=ritu
Bug 1187764: Abort synchronization if our device has gone away. r=jrmuizel a=ritu
Bug 1188613 - Handle attribute mutations with null value. r=pbrosset a=ritu
Bug 1194319 - Correctly deal with all possible ways that initializing the permission manager DB connection can fail; r=mystor a=ritu
Bug 1188752 - Addendum: Make PersistentBufferProviderBasic constructor explicit. r=bustage on a CLOSED TREE a=ritu
Bug 1188752: Ensure persistence of DrawTarget when using InitializeWithSurface. r=jrmuizel a=ritu

New in Firefox 41.0b2 Beta (Aug 18, 2015)

New in Firefox 40.0.2 (Aug 14, 2015)

New in Firefox 40.0.1 (Aug 13, 2015)

New in Firefox 40.0 (Aug 11, 2015)

NEW:
Added protection against unwanted software downloads
User can receive suggested tiles in the new tab page based on categories Firefox matches to browsing history (en-US only).
Hello allows adding a link to conversations to provide context on what the conversation will be about
New style for add-on manager based on the in-content preferences style
Improved scrolling, graphics, and video playback performance with off main thread compositing (GNU/Linux only)
Graphic blocklist mechanism improved: Firefox version ranges can be specified, limiting the number of devices blocked
CHANGED:
Add-on extensions that are not signed by Mozilla will display a warning
NPAPI Plug-in performance improved via asynchronous initialization
Smoother animation and scrolling with hardware vsync (Windows only)
JPEG images use less memory when scaled and can be painted faster
Sub-resources can no longer request HTTP authentication, thus protecting users from inadvertently disclosing login data
HTML5:
IndexedDB transactions are now non-durable by default
Implemented AudioBufferSourceNode.detune to modulate playback rate in cents, a logarithmic unit of measure used for musical intervals
DEVELOPER:
Improved Performance tools in the developer tools: Waterfall view, Call Tree view and a Flame Chart view
New rules view tooltip in the Inspector to tweak CSS Filter values
Console API messages from SharedWorker and ServiceWorker are now displayed in web console
New page ruler highlighting tool that displays lightweight horizontal and vertical rules on a page
Inspector now searches across all content frames in a page
FIXED:
Kannada text does not display properly in built-in pdf viewer
Security fixes:
2015-92 Use-after-free in XMLHttpRequest with shared workers
2015-91 Mozilla Content Security Policy allows for asterisk wildcards in violation of CSP specification
2015-90 Vulnerabilities found through code inspection
2015-89 Buffer overflows on Libvpx when decoding WebM video
2015-88 Heap overflow in gdk-pixbuf when scaling bitmap images
2015-87 Crash when using shared memory in JavaScript
2015-86 Feed protocol with POST bypasses mixed content protections
2015-85 Out-of-bounds write with Updater and malicious MAR file
2015-84 Arbitrary file overwriting through Mozilla Maintenance Service with hard links
2015-83 Overflow issues in libstagefright
2015-82 Redefinition of non-configurable JavaScript object properties
2015-81 Use-after-free in MediaStream playback
2015-80 Out-of-bounds read with malformed MP3 file
2015-79 Miscellaneous memory safety hazards (rv:40.0 / rv:38.2)

New in Firefox 40.0 RC 5 (Aug 8, 2015)

New in Firefox 39.0.3 (Aug 7, 2015)

New in Firefox 40.0 RC 1 (Aug 4, 2015)

New in Firefox 40.0b9 Beta (Jul 31, 2015)

New in Firefox 40.0b8 Beta (Jul 28, 2015)

New in Firefox 40.0b7 Beta (Jul 24, 2015)

New in Firefox 40.0b6 Beta (Jul 22, 2015)

New in Firefox 40.0b4 Beta (Jul 14, 2015)

New in Firefox 40.0b3 Beta (Jul 10, 2015)

New in Firefox 40.0b2 Beta (Jul 7, 2015)

New in Firefox 39.0 (Jul 3, 2015)

New in Firefox 39.0 RC 6 (Jul 1, 2015)

New in Firefox 41.0a2 Developer (Jun 30, 2015)

New in Firefox 39.0 RC 5 (Jun 27, 2015)

New in Firefox 39.0 RC 4 (Jun 25, 2015)

New in Firefox 39.0 RC 3 (Jun 23, 2015)

New in Firefox 39.0b7 Beta (Jun 19, 2015)

New in Firefox 39.0b6 Beta (Jun 16, 2015)

New in Firefox 39.0b5 Beta (Jun 12, 2015)

New in Firefox 39.0b4 Beta (Jun 10, 2015)

New in Firefox 38.0.6 RC 1 (Jun 6, 2015)

New in Firefox 39.0b3 Beta (Jun 5, 2015)

New in Firefox 39.0b2 Beta (Jun 2, 2015)

New in Firefox 38.0.5 (Jun 2, 2015)

New in Firefox 39.0b1 Beta (May 25, 2015)

New in Firefox 38.0.5 RC 3 (May 22, 2015)

New in Firefox 38.0.5b3 Beta (May 19, 2015)

New in Firefox 38.0.5b2 Beta (May 15, 2015)

New in Firefox 38.0.1 (May 15, 2015)

New in Firefox 38.0.1 RC 1 (May 14, 2015)

New in Firefox 38.0 (May 12, 2015)

New:
New tab-based preferences
Ruby annotation support
Share the active tab or window in a Hello conversation - enabled for first half of the beta cycle
Keep track of articles and blog posts with the Reading List - enabled for the first half of the beta cycle
Base for the next ESR release.
Changed:
autocomplete=off is no longer supported for username/password fields
RegExp.prototype.source now returns "(?:)" instead of the empty string for empty regular expressions
Page load times improved by speculative connection warmup
HTML5:
WebSocket now available in Web Workers
Implemented srcset attribute and element for responsive images
Implemented DOM3 Events KeyboardEvent.code
Mac OS X: Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube
BroadcastChannel API implemented
Implemented Encrypted Media Extensions (EME) API to support encrypted HTML5 video/audio playback (Windows Vista or later only)
Automatically download Adobe Primetime Content Decryption Module (CDM) for DRM playback through EME (Windows Vista or later only)
Developer:
Optimized-out variables are now visible in Debugger UI
XMLHttpRequest logs in the web console are now visually labelled and can be filtered separately from regular network requests
WebRTC now has multistream and renegotiation support
copy command added to console
Security fixes:
2015-58 Mozilla Windows updater can be run outside of application directory
2015-57 Privilege escalation through IPC channel messages
2015-56 Untrusted site hosting trusted page can intercept webchannel responses
2015-55 Buffer overflow and out-of-bounds read while parsing MP4 video metadata
2015-54 Buffer overflow when parsing compressed XML
2015-53 Use-after-free due to Media Decoder Thread creation during shutdown
2015-52 Sensitive URL encoded information written to Android logcat
2015-51 Use-after-free during text processing with vertical text enabled
2015-50 Out-of-bounds read and write in asm.js validation
2015-49 Referrer policy ignored when links opened by middle-click and context menu
2015-48 Buffer overflow with SVG content and CSS
2015-47 Buffer overflow parsing H.264 video with Linux Gstreamer
2015-46 Miscellaneous memory safety hazards (rv:38.0 / rv:31.7)

New in Firefox 38.0.5b1 Beta (May 11, 2015)

New in Firefox 38.0 RC 3 (May 9, 2015)

New in Firefox 38.0 RC 2 (May 4, 2015)

New in Firefox 38.0b9 Beta (Apr 30, 2015)

New in Firefox 38.0b7 Beta (Apr 25, 2015)

New in Firefox 38.0b6 Beta (Apr 21, 2015)

New in Firefox 37.0.2 (Apr 20, 2015)

New in Firefox 38.0b5 Beta (Apr 17, 2015)

New in Firefox 37.0.2 RC 1 (Apr 16, 2015)

New in Firefox 38.0b4 Beta (Apr 14, 2015)

New in Firefox 38.0b3 Beta (Apr 10, 2015)

New in Firefox 38.0b2 Beta (Apr 7, 2015)

New in Firefox 37.0.1 (Apr 3, 2015)

New in Firefox 37.0.1 RC 1 (Apr 3, 2015)

New in Firefox 38.0b1 Beta (Mar 31, 2015)

New in Firefox 37.0 (Mar 31, 2015)

Heartbeat user rating system - your feedback about Firefox
Bing search now uses HTTPS for secure searching
New preferences implementation enabled for the first half of the beta cycle
Improved protection against site impersonation via OneCRL centralized certificate revocation
Opportunistically encrypt HTTP traffic where the server supports HTTP/2 AltSvc
Disabled insecure TLS version fallback for site security
Extended SSL error reporting for reporting non-certificate errors
TLS False Start optimization now requires a cipher suite using AEAD construction
Added support for e-mail name constraints in certificates
Improved certificate and TLS communication security by removing support for DSA
Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube
Added support for CSS display:contents
IndexedDB now accessible from worker threads
WebSocket now available in Web Workers
Debug tabs opened in Chrome Desktop, Chrome for Android, and Safari for iOS
New Inspector animations panel to control element animations
New Security Panel included in Network Panel
Debugger panel support for chrome:// and about:// URIs
Added logging of weak ciphers to the web console
Security fixes:
2015-42 Windows can retain access to privileged content on navigation to unprivileged pages
2015-41 PRNG weakness allows for DNS poisoning on Android
2015-40 Same-origin bypass through anchor navigation
2015-39 Use-after-free due to type confusion flaws
2015-38 Memory corruption crashes in Off Main Thread Compositing
2015-37 CORS requests should not follow 30x redirections after preflight
2015-36 Incorrect memory management for simple-type arrays in WebRTC
2015-35 Cursor clickjacking with flash and images
2015-34 Out of bounds read in QCMS library
2015-33 resource:// documents can load privileged pages
2015-32 Add-on lightweight theme installation approval bypassed through MITM attack
2015-31 Use-after-free when using the Fluendo MP3 GStreamer plugin
2015-30 Miscellaneous memory safety hazards (rv:37.0 / rv:31.6)

New in Firefox 37.0 RC 2 (Mar 27, 2015)

New in Firefox 37.0 RC 1 (Mar 25, 2015)

New in Firefox 36.0.4 (Mar 23, 2015)

New in Firefox 36.0.3 (Mar 20, 2015)

New in Firefox 37.0b6 Beta (Mar 17, 2015)

New in Firefox 37.0b5 Beta (Mar 13, 2015)

New in Firefox 37.0b4 Beta (Mar 10, 2015)

New in Firefox 37.0b3 Beta (Mar 6, 2015)

New in Firefox 36.0.1 (Mar 6, 2015)

New in Firefox 36.0.1 RC 2 (Mar 5, 2015)

New in Firefox 37.0b2 Beta (Mar 3, 2015)

New in Firefox 37.0b1 Beta (Feb 24, 2015)

New in Firefox 36.0 (Feb 24, 2015)

NEW:
Pinned tiles on the new tab page can be synced
Support for the full HTTP/2 protocol. HTTP/2 enables a faster, more scalable, and more responsive web.
Locale added: Uzbek (uz)
New preferences implementation enabled for the first half of the beta cycle
CHANGED:
The Flash protected-mode sandbox is disabled on Windows, to evaluate the stability impact of protected mode
-remote option removed
No longer accept insecure RC4 ciphers whenever possible
Phasing out Certificates with 1024-bit RSA Keys
Shut down hangs will now show the crash reporter before exiting the program
Add-on Compatibility
HTML5:
Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube.
Support for the ECMAScript 6 Symbol data type added
unicode-range CSS descriptor implemented
CSSOM-View scroll behavior implemented allowing smooth scrolling of content without custom libraries object-fit and object-position implemented.
Defines how and where the content of a replaced element is displayed isolation CSS property implemented.
Create a new stacking context to isolate groups of boxes to control which blend together
CSS3 will-change property implemented.
Hints the browser of elements that will be modified. The browser will perform some performance optimization for these
Changed JavaScript 'const' semantics to conform better to the ES6 specification.
The const declaration is now block-scoped and requires an initializer. It also can not be redeclared anymore.
implemented for more privacy. Allows to control the content of the HTTP referer header.
Improved ES6 generators for better performance
DEVELOPER:
Eval sources now appear in the Debugger
Debug JavaScript code that is evaluated dynamically, either as a string passed to eval() or as a string passed to the Function constructor
DOM Promises inspection
Inspector: More paste options in markup view
FIXED:
CSS gradients work on premultiplied colors
Fix some unexpected logout from Facebook or Google after restart
SECURITY FIXES:
2015-27 Caja Compiler JavaScript sandbox bypass
2015-26 UI Tour whitelisted sites in background tab can spoof foreground tabs
2015-25 Local files or privileged URLs in pages can be opened into new tabs
2015-24 Reading of local files through manipulation of form autocomplete
2015-23 Use-after-free in Developer Console date with OpenType Sanitiser
2015-22 Crash using DrawTarget in Cairo graphics library
2015-21 Buffer underflow during MP3 playback
2015-20 Buffer overflow during CSS restyling
2015-19 Out-of-bounds read and write while rendering SVG content
2015-18 Double-free when using non-default memory allocators with a zero-length XHR
2015-17 Buffer overflow in libstagefright during MP4 video playback
2015-16 Use-after-free in IndexedDB
2015-15 TLS TURN and STUN connections silently fail to simple TCP connections
2015-14 Malicious WebGL content crash when writing strings
2015-13 Appended period to hostnames can bypass HPKP and HSTS protections
2015-12 Invoking Mozilla updater will load locally stored DLL files
2015-11 Miscellaneous memory safety hazards (rv:36.0 / rv:31.5)

New in Firefox 36.0 RC 2 (Feb 24, 2015)

New in Firefox 36.0b10 Beta (Feb 18, 2015)

New in Firefox 36.0b9 Beta (Feb 13, 2015)

New in Firefox 36.0b8 Beta (Feb 10, 2015)

New in Firefox 36.0b7 Beta (Feb 6, 2015)

New in Firefox 36.0b6 Beta (Feb 3, 2015)

New in Firefox 36.0b5 Beta (Jan 31, 2015)

New in Firefox 36.0b4 Beta (Jan 27, 2015)

New in Firefox 35.0.1 (Jan 26, 2015)

New in Firefox 36.0b3 Beta (Jan 24, 2015)

New in Firefox 36.0b2 Beta (Jan 21, 2015)

New in Firefox 36.0b1 Beta (Jan 14, 2015)

New in Firefox 35.0 (Jan 14, 2015)

New in Firefox 35.0 RC 3 (Jan 9, 2015)

New in Firefox 35.0 RC 2 (Jan 7, 2015)

New in Firefox 35.0 RC 1 (Jan 6, 2015)

New in Firefox 35.0b8 Beta (Dec 31, 2014)

New in Firefox 35.0b6 Beta (Dec 23, 2014)

New in Firefox 35.0b5 Beta (Dec 19, 2014)

New in Firefox 35.0b4 Beta (Dec 17, 2014)

New in Firefox 35.0b3 Beta (Dec 12, 2014)

New in Firefox 35.0b2 Beta (Dec 9, 2014)

New in Firefox 35.0b1 Beta (Dec 2, 2014)

New in Firefox 34.0.5 (Dec 1, 2014)

New in Firefox 34.0.5 RC 1 (Nov 27, 2014)

New in Firefox 34.0 RC 2 (Nov 26, 2014)

New in Firefox 34.0 RC 1 (Nov 25, 2014)

New in Firefox 34.0b11 Beta (Nov 21, 2014)

New in Firefox 34.0b10 Beta (Nov 18, 2014)

New in Firefox 33.1.1 (Nov 15, 2014)

New in Firefox 34.0b9 Beta (Nov 14, 2014)

New in Firefox 34.0b8 Beta (Nov 11, 2014)

New in Firefox 33.1 (Nov 10, 2014)

New in Firefox 33.0.3 (Nov 7, 2014)

New in Firefox 33.1 RC 2 (Nov 6, 2014)

New in Firefox 33.0.3 RC 2 (Nov 6, 2014)

New in Firefox 34.0b6 Beta (Nov 4, 2014)

New in Firefox 34.0b5 Beta (Oct 31, 2014)

New in Firefox 33.1 RC 1 (Oct 30, 2014)

New in Firefox 33.0.2 (Oct 29, 2014)

New in Firefox 34.0b4 Beta (Oct 28, 2014)

New in Firefox 33.0.1 (Oct 25, 2014)

New in Firefox 34.0b3 Beta (Oct 24, 2014)

New in Firefox 33.0.1 RC 1 (Oct 22, 2014)

New in Firefox 34.0b2 Beta (Oct 21, 2014)

New in Firefox 34.0b1 Beta (Oct 14, 2014)

New in Firefox 33.0 (Oct 14, 2014)

New in Firefox 33.0 RC 2 (Oct 13, 2014)

New in Firefox 33.0 RC 1 (Oct 8, 2014)

New in Firefox 33.0b9 Beta (Oct 3, 2014)

New in Firefox 33.0b8 Beta (Oct 1, 2014)

New in Firefox 32.0.3 (Sep 25, 2014)

New in Firefox 32.0.3 RC 1 (Sep 24, 2014)

New in Firefox 33.0b6 Beta (Sep 23, 2014)

New in Firefox 33.0b5 Beta (Sep 19, 2014)

New in Firefox 32.0.2 (Sep 19, 2014)

New in Firefox 32.0.2 RC 1 (Sep 18, 2014)

New in Firefox 33.0b4 Beta (Sep 16, 2014)

New in Firefox 32.0.1 (Sep 13, 2014)

New in Firefox 33.0b3 Beta (Sep 12, 2014)

New in Firefox 32.0.1 RC 1 (Sep 11, 2014)

New in Firefox 33.0b2 Beta (Sep 9, 2014)

New in Firefox 33.0b1 Beta (Sep 5, 2014)

New in Firefox 32.0 (Sep 3, 2014)

New in Firefox 32.0b9 Beta (Aug 23, 2014)

New in Firefox 32.0b8 Beta (Aug 20, 2014)

New in Firefox 32.0b7 Beta (Aug 16, 2014)

New in Firefox 32.0b6 Beta (Aug 13, 2014)

New in Firefox 32.0b5 Beta (Aug 9, 2014)

New in Firefox 32.0b4 Beta (Aug 5, 2014)

New in Firefox 32.0b3 Beta (Aug 1, 2014)

New in Firefox 32.0b2 Beta (Jul 29, 2014)

New in Firefox 32.0b1 Beta (Jul 23, 2014)

New in Firefox 31.0 (Jul 22, 2014)

New in Firefox 31.0 RC 1 (Jul 15, 2014)

New in Firefox 31.0b9 Beta (Jul 11, 2014)

New in Firefox 31.0b8 Beta (Jul 8, 2014)

New in Firefox 31.0b7 Beta (Jul 4, 2014)

New in Firefox 31.0b6 Beta (Jul 1, 2014)

New in Firefox 31.0b5 Beta (Jun 27, 2014)

New in Firefox 31.0b4 Beta (Jun 24, 2014)

New in Firefox 31.0b3 Beta (Jun 21, 2014)

New in Firefox 31.0b2 Beta (Jun 17, 2014)

New in Firefox 31.0b1 Beta (Jun 11, 2014)

New in Firefox 30.0 (Jun 11, 2014)

New in Firefox 30.0 RC 2 (Jun 6, 2014)

New in Firefox 30.0 RC 1 (Jun 4, 2014)

New in Firefox 30.0b9 Beta (May 30, 2014)

New in Firefox 30.0b8 Beta (May 28, 2014)

New in Firefox 30.0b7 Beta (May 23, 2014)

New in Firefox 30.0b6 Beta (May 21, 2014)

New in Firefox 30.0b5 Beta (May 16, 2014)

New in Firefox 30.0b4 Beta (May 14, 2014)

New in Firefox 29.0.1 (May 9, 2014)

New in Firefox 30.0b3 Beta (May 9, 2014)

New in Firefox 29.0.1 RC 1 (May 6, 2014)

New in Firefox 30.0b2 Beta (May 6, 2014)

New in Firefox 30.0b1 Beta (Apr 30, 2014)

New in Firefox 29.0 (Apr 30, 2014)

What’s New:
New: Significant new customization mode makes it easy to personalize your Web experience to access the features you use the most (learn more)
New: A new, easy to access menu sits in the right hand corner of Firefox and includes popular browser controls
New: Sleek new tabs provide an overall smoother look and fade into the background when not active
New: An interactive onboarding tour to guide users through the new Firefox changes
New: The ability to set up Firefox Sync by creating a Firefox account (learn more)
New: Gamepad API finalized and enabled (learn more)
New: HTTPS used for Yahoo Searches performed in en-US locale
New: Malay [ma] locale added
Changed: Clicking on a W3C Web Notification will switch to the originating tab
Developer: 'box-sizing' (dropping the -moz- prefix) implemented (learn more)
Developer: Console object available in Web Workers (learn more)
Developer: Promises enabled by default (learn more)
Developer: SharedWorker enabled by default
Developer: implemented and enabled
Developer: implemented and enabled
Developer: Enabled ECMAScript Internationalization API
Developer: Add-on bar has been removed, content moved to navigation bar
Developer: Implemented URLSearchParams from the URL specification (see MDN for details )
Various security fixes:
MFSA 2014-47 Debugger can bypass XrayWrappers with JavaScript
MFSA 2014-46 Use-after-free in nsHostResolve
MFSA 2014-45 Incorrect IDNA domain name matching for wildcard certificates
MFSA 2014-44 Use-after-free in imgLoader while resizing images
MFSA 2014-43 Cross-site scripting (XSS) using history navigations
MFSA 2014-42 Privilege escalation through Web Notification API
MFSA 2014-41 Out-of-bounds write in Cairo
MFSA 2014-40 Firefox for Android addressbar suppression
MFSA 2014-39 Use-after-free in the Text Track Manager for HTML video
MFSA 2014-38 Buffer overflow when using non-XBL object as XBL
MFSA 2014-37 Out of bounds read while decoding JPG images
MFSA 2014-36 Web Audio memory corruption issues
MFSA 2014-35 Privilege escalation through Mozilla Maintenance Service Installer
MFSA 2014-34 Miscellaneous memory safety hazards (rv:29.0 / rv:24.5)

New in Firefox 31.0a2 Aurora (Apr 29, 2014)

New in Firefox 29.0 RC 1 (Apr 22, 2014)

New in Firefox 29.0b9 Beta (Apr 18, 2014)

New in Firefox 29.0b8 Beta (Apr 15, 2014)

New in Firefox 29.0b7 (Apr 11, 2014)

New in Firefox 29.0b6 (Apr 8, 2014)

New in Firefox 29.0b5 (Apr 4, 2014)

New in Firefox 29.0b3 (Mar 28, 2014)

New in Firefox 29.0b2 (Mar 25, 2014)

New in Firefox 29.0b1 (Mar 19, 2014)

New in Firefox 28.0 (Mar 19, 2014)

New in Firefox 28.0b9 Beta (Mar 7, 2014)

New in Firefox 27.0.1 (Feb 14, 2014)

New in Firefox 27.0.1 RC 1 (Feb 13, 2014)

New in Firefox 27.0 (Feb 5, 2014)

New in Firefox 27.0 Beta (Dec 17, 2013)

New in Firefox 26.0 (Dec 10, 2013)

New in Firefox 26.0b3 Beta (Nov 8, 2013)

New in Firefox 26.0b2 Beta (Nov 5, 2013)

New in Firefox 25.0 (Oct 29, 2013)

New in Firefox 24.0 (Sep 18, 2013)

NEW: Support for new scrollbar style in Mac OS X 10.7 and newer
NEW: Implemented Close tabs to the right
NEW: Social: Ability to tear-off chat windows to view separately by simply dragging them out
CHANGED: Accessibility related improvements on using pinned tabs (see 577727)
CHANGED: Removed support for Revocation Lists feature (see 867465)
CHANGED: Performance improvements on New Tab Page loads (see 791670)
DEVELOPER: Major SVG rendering improvements around Image tiling and scaling (see 600207 )
DEVELOPER: Improved and unified Browser console for enhanced debugging experience, replacing existing Error console
DEVELOPER: Removed support for sherlock files that are loaded from application or profile directory
FIXED: Replace fixed-ratio audio resampler in webrtc.org capture code with Speex resampler and eliminate pseudo-44000Hz rate ( see 886886)
Security fixes:
MFSA 2013-92 GC hazard with default compartments and frame chain restoration
MFSA 2013-91 User-defined properties on DOM proxies get the wrong "this" object
MFSA 2013-90 Memory corruption involving scrolling
MFSA 2013-89 Buffer overflow with multi-column, lists, and floats
MFSA 2013-88 compartment mismatch re-attaching XBL-backed nodes
MFSA 2013-87 Shared object library loading from writable location
MFSA 2013-86 WebGL Information disclosure through OS X NVIDIA graphic drivers
MFSA 2013-85 Uninitialized data in IonMonkey
MFSA 2013-84 Same-origin bypass through symbolic links
MFSA 2013-83 Mozilla Updater does not lock MAR file after signature verification
MFSA 2013-82 Calling scope for new Javascript objects can lead to memory corruption
MFSA 2013-81 Use-after-free with select element
MFSA 2013-80 NativeKey continues handling key messages after widget is destroyed
MFSA 2013-79 Use-after-free in Animation Manager during stylesheet cloning
MFSA 2013-78 Integer overflow in ANGLE library
MFSA 2013-77 Improper state in HTML5 Tree Builder with templates
MFSA 2013-76 Miscellaneous memory safety hazards (rv:24.0 / rv:17.0.9)

New in Firefox 24.0 (Sep 16, 2013)

New in Firefox 23.0.1 (Aug 17, 2013)

New in Firefox 24.0b1 Beta (Aug 10, 2013)

New in Firefox 23.0 (Aug 7, 2013)

NEW: Mixed content blocking enabled to protects users from man-in-the-middle attacks and eavesdroppers on HTTPS pages (learn more)
NEW: Options panel created for Web Developer Toolbox
CHANGED: "Enable JavaScript" preference checkbox has been removed and user-set values will be reset to the default
CHANGED: Updated Firefox Logo
CHANGED: Improved about:memory's functional UI
CHANGED: Simplified interface for notifications of plugin installation
CHANGED: Enabled DXVA2 on Windows Vista+ to accelerate H.264 video decoding
CHANGED: Users can now switch to a new search provider across the entire browser
CHANGED: CSP policies using the standard syntax and semantics will now be enforced
CHANGED: rendering improvements (see bug 838675)
CHANGED: Replace fixed-ratio audio resampler in webrtc.org capture code with Speex resampler and eliminate pseudo-44000Hz rate
CHANGED: "Load images automatically" and Always show the tab bar" checkboxes removed from preferences and reset to defaults
DEVELOPER: HTML5 form control implemented
DEVELOPER: Write more accessible pages on touch interfaces with new ARIA role for key buttons
DEVELOPER: Social share functionality
DEVELOPER: Added unprefixed requestAnimationFrame
DEVELOPER: Implemented a global browser console
DEVELOPER: Dropped blink effect from text-decoration: blink; and completely removed element
DEVELOPER: New feature in toolbox: Network Monitor
Various bug fixes:
MFSA 2013-75 Local Java applets may read contents of local file system
MFSA 2013-74 Firefox full and stub installer DLL hijacking
MFSA 2013-73 Same-origin bypass with web workers and XMLHttpRequest
MFSA 2013-72 Wrong principal used for validating URI for some Javascript components
MFSA 2013-71 Further Privilege escalation through Mozilla Updater
MFSA 2013-70 Bypass of XrayWrappers using XBL Scopes
MFSA 2013-69 CRMF requests allow for code execution and XSS attacks
MFSA 2013-68 Document URI misrepresentation and masquerading
MFSA 2013-67 Crash during WAV audio file decoding
MFSA 2013-66 Buffer overflow in Mozilla Maintenance Service and Mozilla Updater
MFSA 2013-65 Buffer underflow when generating CRMF requests
MFSA 2013-64 Use after free mutating DOM during SetBody
MFSA 2013-63 Miscellaneous memory safety hazards (rv:23.0 / rv:17.0.8)

New in Firefox 22.0 (Jun 26, 2013)

New in Firefox 21.0 (May 15, 2013)

New in Firefox 20.0.1 (Apr 11, 2013)

New in Firefox 21.0b2 Beta (Apr 9, 2013)

New in Firefox 19.0.2 (Mar 8, 2013)

New in Firefox 20.0b3 Beta (Mar 7, 2013)

New in Firefox 19.0 (Feb 20, 2013)

New in Firefox 19.0b6 Beta (Feb 13, 2013)

New in Firefox 18.0.1 (Jan 19, 2013)

New in Firefox 19.0b2 Beta (Jan 17, 2013)

New in Firefox 18.0 (Jan 8, 2013)

New in Firefox 17.0.1 (Dec 3, 2012)

New in Firefox 17.0 (Nov 20, 2012)

New in Firefox 16.0.2 (Oct 27, 2012)

New in Firefox 17.0b1 Beta (Oct 12, 2012)

New in Firefox 16.0.1 (Oct 12, 2012)

New in Firefox 16.0 (Oct 12, 2012)

New in Firefox 15.0.1 (Oct 11, 2012)

New in Firefox 14.0.1 (Jul 18, 2012)

New in Firefox 13.0 Final (Jun 6, 2012)

New in Firefox 13.0b1 Beta (Apr 26, 2012)

New in Firefox 12.0 Final (Apr 25, 2012)

New in Firefox 12.0b3 Beta (Mar 29, 2012)

New in Firefox 11.0 (Mar 14, 2012)

New in Firefox 10.0.2 (Feb 17, 2012)

New in Firefox 10.0.1 (Feb 10, 2012)

New in Firefox 12.0a2 Aurora (Feb 4, 2012)

New in Firefox 10.0 (Feb 3, 2012)

New in Firefox 10.0b1 Beta (Dec 23, 2011)

New in Firefox 9.0 (Dec 20, 2011)

New in Firefox 9.0b6 Beta (Dec 14, 2011)

New in Firefox 8.0.1 (Nov 22, 2011)

New in Firefox 10.0a2 Aurora (Nov 12, 2011)

New in Firefox 8.0 (Nov 6, 2011)

New in Firefox 7.0.1 (Sep 30, 2011)

New in Firefox 7.0 (Sep 27, 2011)

New in Firefox 6.0.1 (Aug 31, 2011)

New in Firefox 7.0b1 Beta (Aug 20, 2011)

New in Firefox 6.0 (Aug 17, 2011)

New in Firefox 6.0 Beta 2 (Jul 16, 2011)

New in Firefox 5.0.1 (Jul 12, 2011)

New in Firefox 6.0 Beta 1 (Jul 9, 2011)

New in Firefox 7.0a2 Aurora (Jul 8, 2011)

New in Firefox 5.0 (Jun 22, 2011)

New in Firefox 5.0b7 RC (Jun 16, 2011)

New in Firefox 6.0a2 Aurora (May 28, 2011)

New in Firefox 5.0 Beta (May 21, 2011)

New in Firefox 4.0.1 (Apr 29, 2011)

New in Firefox 3.6.17 (Apr 29, 2011)

New in Firefox 4.0 (Mar 23, 2011)

Firefox 4 is available in over 80 languages
Uses JägerMonkey, a new, faster JavaScript engine that is up to six times faster than Firefox 3.6
Support for the Do Not Track ("DNT") header that allows users to opt-out of behavioural advertising
Firefox Sync is included by default, allowing you to securely synchronize between multiple computers and mobile devices
Certain graphics rendering operations are now hardware-accelerated using Direct3D 9 on Windows XP, Direct3D 10 on Windows Vista and 7, and OpenGL on Mac OS (OpenGL on Linux will be supported in the future)
Direct2D Hardware Acceleration is now on by default for Windows 7 users
WebGL is enabled on all platforms that have a capable graphics card with updated drivers
Native support for the HD HTML5 WebM video format, hardware accelerated where available
Firefox button has a new look for Windows Vista and Windows 7 users
Tabs are now on top by default on Windows, Mac OS X, and Linux
You can search for and switch to already open tabs in the Smart Location Bar
The stop and reload buttons have been merged into a single button on Windows, Mac OS X, and Linux
The Bookmarks Toolbar has been replaced with a Bookmarks Button by default (you can switch it back if you'd like)
Crash protection for Windows, Linux, and Mac OS X when there is a crash in the Adobe Flash, Apple Quicktime or Microsoft Silverlight plugins
You can turn any tab into an "App Tab" by right-clicking on it and selecting "Make into App Tab" from the context menu
The default homepage design has been refreshed
Overhaul of the bookmarks and history code, enabling faster bookmarking and startup performance
Per-compartment garbage collection is now enabled, reducing work done during complex animations
Additional polish for the Firefox Add-ons Manager
Improved web typography using OpenType with support for ligatures, kerning and font variants
Web developers can animate content using CSS Transitions
Responsiveness and scrolling improvements from the new retained layers layout system
HTML5 Forms API makes web based forms easier to implement and validate
Support for the new proposed Audio Data API
Support for HSTS security protocol allowing sites to insist that they only be loaded over SSL
A new feature called Panorama gives users a visual overview of all open tabs, allowing them to be sorted and grouped
An experimental API is included to provide more efficient Javascript animations
Firefox now supports the HTML5 video "buffered" property
Changes to how XPCOM components are registered in order to help startup time and process separation
New Addons Manager and extension management API (UI will be changed before final release)
Significant API improvements are available for JS-ctypes, a foreign function interface for extensions
CSS Transitions are partially supported
Core Animation rendering model for plugins on Mac OS X. Plugins which also support this rendering model can now draw faster and more efficiently
Web developers can update the URL field without reloading the page using HTML History APIs
More responsive page rendering using lazy frame construction
Link history lookup is done asynchronously to provide better responsiveness during pageload
CSS :visited selectors have been changed to block websites from being able to check a user's browsing history
New HTML5 parser
Support for more HTML5 form controls
Web authors can now get touch events from Firefox users on Windows 7 machines
A new way of representing values in JavaScript that allows Firefox to execute heavy, numeric code (used for things like graphics and animations) more efficiently

New in Firefox 3.5.18 (Mar 23, 2011)

New in Firefox 3.6.16 (Mar 23, 2011)

New in Firefox 4.0 RC2 (Mar 19, 2011)

New in Firefox 4.0 RC 1 (Mar 9, 2011)

General stability, performance, and compatibility improvements.
632833 - Crash [@ nsGlobalWindow::LeaveModalState(nsIDOMWindow*) ]
626691 - "Log In To My T-Mobile" flash text is mispositioned, when loading "My T-Mobile" page in background t…
635397 - when tabbar and menubar have unified appearance, tabbar should be just as draggable as menubar
635400 - crash [@ nsBuiltinDecoder::GetBuffered]
635401 - Segfault when checking name of graphics driver vendor
634380 - Problem with drop down menus on Nike and also on other sites
635405 - Zooming windowless plugin frame can cause it to "bleed" outside bounds
628048 - hovered highlight on menu item sticks around too long after moving to a different menu item
636945 - add downcasting for nsRootAccessible
634387 - [Mac] Firefox 4.0b12pre crash [@ mozalloc_abort | NS_DebugBreak_P | mozilla::plugins::PPluginInstanc…
620206 - nsFrameMessageManager::ReceiveMessage returns non-nsresult values
636692 - Remove the Hotmail-specific hack that forces the old parser for document.open()
513616 - [meta] nanojit: clean up register allocator
635417 - Regular expression bug (breaks splinter patch review)
635418 - TabShow & TabHide should cause saveStateDelayed
629167 - FFT algorithm runs 5X faster with Tracemonkey-only than with Jaeger and Trace Monkeys working togeth…
635420 - Clicking on content within Normal tab of Composer and stops switching to other tabs
623136 - speed up font loading on android
633890 - Assertion failure: prop == (JSProperty*) shape
637987 - IPDL protocols used in unit tests are always built, even without --enable-ipdl-tests
633892 - Blacklist NVIDIA NVS 3100M on driver 8.17.12.5896
635943 - Check Items.arrange() calls to make sure tab bounds are correctly calculated
636968 - Startup crash [@ InitDwriteBG ] in virtual environments
619565 - "Assertion failure: scopeChain_ == calleeValue().toObject().getParent()"
633390 - Crop long link URLs in the middle instead of at the end (as the location bar hover link did)
636465 - misspelled words in the subject line get underlined despite disabled "Spell Check As You Type" in a …
635442 - Crash [@ nsSVGComponentTransferFunctionElement::DidAnimateNumberList]
630835 - Transition paint wrong fragments at the end of transition for 1-2 seconds.
622942 - Gmail's chat contact list layer is not opaque when scrolling on OS X
536630 - TM: awful LIR generated for bitwise-and.js (and everything else)
635451 - Firefox changes font mid-line on some numerals
632893 - Remove useless Cc/Ci/Cr/Cu/Components.*/Services.jsm from Firefox tests
635966 - elfhack fails with llvm LTO
635968 - JM: Crash on Google Spreadsheet
387138 - immediately after instantiation (cut/paste or subscribe), livemark looks like a regular folder in so…
632587 - implement getSupportedExtensions and isContextLost
632901 - TM: crash when assigning to function.arguments
635462 - "/tests/dom/tests/mochitest/ajax/prototype/test_Prototype.html or /tests/dom/tests/mochitest/bugs/te…
635465 - JavaScript menu is not working on sports.ru
635980 - Frequent harmless ASSERTION Nv3DVStreaming Nv3DVControl failed!
463950 - When feed is refreshed in Thunderbird, in feed starts playing
636495 - Make enabling profilers actually --enable-profiling
626768 - Startup crash [@ mozalloc_abort(char const* const) | mozcrt19.dll@0x1327f | nsCycleCollectorGCHookRu…
635475 - nsIdleServiceDaily can cause pointer corruption
633941 - Mac OS X "Open with..." / double-click on "web" file horked (browser launches without actually loadi…
562262 - fix license in a11y files
626617 - Remove Termiadur search plug-in on major update to 4.0
637019 - regression at www.staples.com - Sorting feature doesn't work (Sort by A-Z; Z-A; etc)
631388 - Investigate not centering plugin images in their frame if the frame/image sizes mismatch
624733 - Add .masr (Egypt) to IDN TLD whitelist
634974 - JavaScript strict warning: chrome://browser/content/tabview.js, line 3274: anonymous function does n…
629857 - Gray bar is added after repainting layer
636002 - better messages about attrib index validation
627729 - Selectively use the old HTML parser for Hotmail to work around repeated reloading
636008 - [Maemo6] Fennec crashes on startup, with Xlib error.
632423 - Text poorly rendered with hardware acceleration off (most noticeable with white text)
632941 - statuspanel's minimum width should be an em value and max width should be a percentage value
629358 - Baum Retec AG Cobra screen reader popup compatibility issue
637040 - iframe embedding youtube not displaying in os x
637032 - Repeated Console messages in the Web Console not showing number
609396 - Some Frames are rendered inconsistently after restart.
602558 - MSVC10 fails to compile with Google OTS source
621686 - Enable IDN for .ua
637559 - Add logging to Android Bridge
634132 - The page flickers/flashes black when scrolling the page while a flash video (on BBC, Engadget, and p…
635005 - new RegExp(undefined) should work like new RegExp("")
637901 - Video in youtube goes white
635008 - browser hangs every time on the "categorize your question" page on yahoo answers and needs to be kil…
386690 - Negative width attribute and percentage height on causes "ASSERTION: reflow stat…
635014 - Don't draw the checkerboard behind undefined content in "sync scrolling mode"
588426 - Restoring multiple solely hidden tabs (after crash) breaks session restore
621707 - Add gob.ec to PSL
621710 - Add bv.nl to PSL
631491 - toolbar's iconsize attribute is not updated correctly after switching themes
603798 - our tabs look great on XP but don't fit as well with Windows 7 and aero
623768 - Pressing Backspace in Panorama causes last focused tab to navigate backwards
636219 - JM: Interpreter's useMethodJIT flag needs to be reset when entering a new function
638106 - CKEditor document should be editable
607900 - [startup-notification] Two windows started when Firefox launched for the first times
634906 - Allow CORS from nsXmlHttpRequest when script is loaded from file
636613 - Let WebGL mochitest run on Windows XP
638116 - use different background gradient colors in split menu buttons in Firefox Button
634534 - Firefox 4 crash Silverlight video [@ mozalloc_abort(char const* const) | mozcrt19.dll@0x1327f | mozi…
601768 - Ensure it's safe to hand a function to a sandbox
635051 - revert experienced_first_use to experienced_first_run
634542 - Spike in crashes [@ call_trace ] among users with Firebug installed + [@ JSStackFrame::callObj() ]
591537 - Freeze UA build id for Firefox branded builds
635059 - Update WebGL test suite to version 1.0.0 from khronos.org
636086 - build bustage when building with --disable-pango
637385 - TM: Assertion failure: obj == globalObj, at ../jstracer.cpp:15253
636088 - Blocked LSP: Microsoft Proxy Client / Microsoft Firewall Client Service Provider
635068 - WebGL test array-unit-tests.html fails
636093 - "ABORT: Shadow layers can't be destroyed during txns!: '!HasShadow() || !BasicManager()->InTransacti…
636609 - Remove DEBUG_GL_ERROR_CHECK
636611 - Block WebGL on Mac OS X 10.5 (not on 10.6)
633462 - Talos turns orange on "###!!! [Child][RPCChannel] Error: Channel closing: too late to send/recv, mes…
628938 - Treewalker not working properly in Mozilla Treewalker Demo
630306 - "jsobj.h:1239: warning: inline function 'JSCompartment* JSObject::getCompartment() const' used but n…
636877 - Improve android restarts
635768 - pages print improperly
636114 - Crash [@ PluginBackgroundSink::~PluginBackgroundSink() ]
638414 - Missing toString() function on Array.prototype - TypeError: Array.prototype.toString called on incom…
633465 - Turn off bug 591836 workaround on Win64
635608 - Clean up sizemode=normal & disablechrome styling for aero glass
636637 - "e is not defined" error while trying to log "Error while loading thumbnail"
634590 - Unqualified function invocation doesn't use the global object the property was gotten from as |this|
634593 - Assertion failure: proto->isNative(), at jsobjinlines.h:917
636131 - iBus freezes when it retrieves surrounding text and if the caret is at end of line (IA__gtk_im_conte…
636143 - Full screen tab bar doesn't drop down after minimize and top of content is cut off.
606960 - crash [@ js::Interpret(JSContext*, JSStackFrame*, unsigned int, JSInterpMode) ]
621411 - Hardware acceleration in Firefox/SeaMonkey causes Oracle VirtualBox 3.2/4.0 to crash
633074 - Zoom in animation is not shown for tabs deep within stacks
637683 - crash [@ memcpy | NS_CopySegmentToBuffer(nsIInputStream*, void*, char const*, unsigned int, unsigned…
626421 - Non-clickable area on top of each tab in Windows XP (tabs in titlebar)
636666 - paste option doesn't appear in context menu for text boxes in content on android
619773 - WebGL: Crash with blue screen : "NMI: Parity Check / Memory Parity Error" with ATI Mobility FireGL V…
637184 - Missing newline at end of file in MacIOSurfaceImageOGL.h
631553 - crash [@ PL_DHashTableOperate | nsFrameScriptExecutor::LoadFrameScriptInternal]
627464 - Annotate crash reports about gfx features in use
636169 - Web Console notifications needed for customization via Addons
629514 - Use public domain headers for our tests
627979 - [clang] "cannot compile this __asm__ yet" in xptcinvoke_x86_64_unix
615693 - Improve the inactive window appearance of tabs-on-top
623405 - svg text rotation reftest failures on WinXP: anim-text-rotate-01.svg & dynamic-text-04.svg
636176 - Sync should not sync general.autoScroll
636689 - Rename the HTML5 parser pref in order to reset it for everyone who has flipped it during the beta cy…
635666 - WebGL crash [@mozilla::WebGLContext::CopyTexSubImage2D]
635155 - Get full JIT-tests coverage back
635156 - typos in test svg files.
624917 - undo close tab does not restore page with frameset
637206 - Random pauses while watching Hulu videos
524761 - Intermittent failure in test_resolveNullBookmarkTitles.js
634648 - re-enable tests disabled due to debug shell reftest assertion: !CompartmentHasLiveScripts(comp)
638218 - Asynchronous policy-uri fetching causes connection problems when using NTLM proxy
632612 - Minor improvements to js_DumpObject
620326 - Intermittent failure in /tests/content/media/test/test_playback.html | Test timed out.
633133 - Testing for named items in HTMLCollections using 'in' operator always returns false
635696 - restore focus after "Undo Close Group" of last group
612872 - HAL/Supernova needs more sophisticated window emulation
635195 - Assertion failure: !wp->setter, at jsdbgapi.cpp:781
615741 - too large canvases don't draw and are black
553278 - Video should decode into buffers allocated by layer backend we are targeting.
637401 - [regression] Console message nodes do not have unique IDs anymore
638276 - Update (and fix) nsTextEditorState.h documentation
635594 - Assertion failure: !tm->recorder, at jstracer.cpp:7131
414690 - match case checkbox and label not aligned vertically with find toolbar buttons
631119 - Dummy popup widgets created in content process can interrupt IME state
635728 - Favicon background must match group item background color
617297 - Fennec 4.0b3pre Crash Report [@ nsXPConnect::GetPrincipal] [@ nsScriptSecurityManager::doGetObjectPr…
609106 - Add plugin-container.exe to ShimInclusionList via installer
635733 - Weird transparency when dragging tabs out of groups
635737 - Zoom animation frame is rotated when we zoom out of a non-top stacked tab
637278 - Full CPU load as long as o2online.de is displayed with hardware acceleration disabled
637282 - Crash [@ mozalloc_abort(char const* const) | NS_DebugBreak_P | mozilla::plugins::PPluginInstance::Tr…
632379 - Can't select some bookmarks
594596 - Crash in [@ nsMenuPopupFrame::CreateWidgetForView(nsIView*) ]
613221 - TypeInference: make inference structures GC safe
636776 - Crash [@ nsSHEntry::GetParent(nsISHEntry**) ][@ @0x0 | nsSHEntry::GetParent(nsISHEntry**) ][@ nsDocS…
638318 - Page starting with lots of NUL chars is incorrectly sniffed as UTF-16BE (with HTML5 parser enabled)
635844 - Update pushState to latest spec. Again.
635252 - Autocomplete textbox gets corrupted after customizing toolbars
634942 - HelperApp launch is broken with GIO
621432 - Assertion failure: script->main code + script->length
636281 - crash [@ -[ChildView setMarkedText:selectedRange:]]
636795 - PROCESS-CRASH | test_index_messages_imap_online_to_offline.js (and others) crash after latest tracem…
633725 - docload_wnd.xul (and nsRootAcc_wnd.xul) tries to load about:robots which is Firefox specific (atm)
601988 - Translated C++ code is not as fast as it could be
637321 - Fix tests that try to use the 'telephone' input type instead of the 'tel' input type
634454 - The Find bar at the bottom of the page keeps going away
633741 - Assertion failure: !cx->isExceptionPending(), at ../jscntxtinlines.h:704
636817 - Video only plays on mouseOver
620434 - useless null check of result in nsXULTreeBuilder::ReplaceMatch
636820 - Test for bug 634590 fails with -a -m
635286 - ":not()" pseudo class in ":-moz-any()" selector doesn't work correctly
627096 - [Meta] Panorama BetaN
631194 - Overlay for connecting / waiting / loading status messages is no longer "small"
636655 - Creating large textnodes became slower since 1.9.2
635665 - nsPrefBranch::GetComplexValue code incorrect after e10s merge
476570 - need an message to console or in the page when src not found for video tag
577438 - Make NodeIterator and TreeWalker not use GetChildAt
586145 - JM: improve string concatenation speed in date-format-xparb.js
565667 - 'Tools' > 'Add-ons' only works when browser window is in the foreground
630180 - ###!!! ASSERTION: No parent accessible where we're not direct child of window: 'xpParentAcc', file .…
596901 - "ASSERTION: Attempting to nest call to BeginSecureKeyboardInput" when iframes fight over password-fi…
635814 - add shellName and shellVersion to nsSystemInfo
570279 - Tab+NavBar Connecting Curve Adjustments
629160 - Generating CASE_EXIT for some default cases in tableswitch when tracing
636828 - browser.js nsINavBookmarkObserver::onItemAdded incorrectly expects aURI when folder added
637200 - GET-request to www.youtube.com is removed from WebConsole
634745 - Fix ARM SIMD/NEON tests to work with LTO
637361 - REOPEN : SSL pages don't work when using a NTLM proxy
631733 - When idle the GC holds on to unused chunks indefinitely
630201 - Crash [@ nsTArray::Clear() ] with pre-Windows-RTM ver…
632763 - Block level links and dynamic HTML
633788 - "closing last tab" inconsistency between main browser window and panorama
604944 - new crash starting in 20101015 nightlies [@js_GetReservedSlot(JSContext*, JSObject*, unsigned long, …
627649 - [Mac] Some events incorrectly passed to a plugin that occur over the plugin
613314 - Firefox/4.0b8pre crash in [@ nsWindow::IPCWindowProcHandler(unsigned int&, unsigned int&, long&) ] m…
636356 - WebGL crash [@mozilla::WebGLBuffer::ZeroDataIfElementArray]
626678 - Firefox becomes unresponsive when docking or undocking my laptop
636870 - Using webgl on optimus hardware causes instant crash
637004 - Crash [@ mozilla::plugins::PluginInstanceChild::EnsureCurrentBuffer() ]
523928 - Partner contact for McAffee
636364 - Followup fixes and tests in wake of global |this| binding change (shell failure on js1_8_5/regress/r…
636365 - Add separate GCTIMER interval for sweeping Shapes
637390 - Test interpreter only in jit-tests
73681 - RANGE:Child Nodes of Attr Nodes have a parentNode property set to null.
611795 - Repeated messages in the Web Console should be collapsed into one
633305 - about:memory should display memory reporters that live in the child process
637915 - nsJNIString is leaky with zero length strings.
634844 - Non-animated plugins constantly reupload image with accelerated layers and async rendering
636894 - Audio 'MozAudioAvailable' event timing behaving poorly
630693 - Web console's copying adds extra newline between groups.
635873 - Assertion failure: compartment == rt->gcCurrentCompartment
635362 - Assertion fails when closing group item
586212 - Don't carry out the command when clicking on a disabled splitmenu
631270 - Status panel gets in way / obscures a Find result at the bottom of the page
628049 - Improve the hover styling of split menus in the Firefox menu
636906 - GFX blacklisting not affecting WebGL?
632817 - Cannot filter search for NET events in the Web console
635892 - Invalid HTTP version triggers text/plain or text/xml rendering
635668 - The zoom in animation doesn't work for new tab by group "+" button or double click on group or empty…
636408 - When opening stack window the titles of the website are not visible
624636 - Allow reftests to set a "displayport" and "view transform"
596478 - Intermittent fail in layout/reftests/svg/image/img-dyn-1.html
556117 - Either breakage or missed fix in nsPNGDecoder.cpp in 1.9.0.19

New in Firefox 3.6.15 (Mar 5, 2011)

New in Firefox 3.6.14 (Mar 2, 2011)

New in Firefox 3.5.17 (Mar 2, 2011)

New in Firefox 4.0 Beta 12 (Feb 25, 2011)

New in Firefox 4.0 Beta 11 (Feb 8, 2011)

New in Firefox 4.0 Beta 10 (Jan 25, 2011)

New in Firefox 4.0 Beta 8 (Dec 21, 2010)

New in Firefox 3.6.13 / 3.5.16 (Dec 10, 2010)

New in Firefox 3.5.15 (Oct 28, 2010)

New in Firefox 3.6.12 (Oct 28, 2010)

New in Firefox 3.6.11 / 3.5.14 (Oct 20, 2010)

New in Firefox 3.6.10 / 3.5.13 (Sep 16, 2010)

New in Firefox 4.0 Beta 6 (Sep 15, 2010)

New in Firefox 4.0 Beta 5 (Sep 8, 2010)

New in Firefox 3.6.9 (Sep 8, 2010)

New in Firefox 3.5.12 (Sep 8, 2010)

New in Firefox 4.0 Beta 4 (Aug 25, 2010)

New in Firefox 4.0 Beta 2 (Jul 28, 2010)

New in Firefox 3.6.8 (Jul 24, 2010)

New in Firefox 3.6.7 (Jul 24, 2010)

New in Firefox 4.0 Beta 1 (Jul 7, 2010)

New in Firefox 3.6.4 (Jun 23, 2010)

New in Firefox 3.6.4 Build 1 Beta (Apr 21, 2010)

New in Firefox 3.7 Alpha 4 (Apr 9, 2010)

New in Firefox 3.6.3 Plugin 1 (Apr 9, 2010)

New in Firefox 3.6.3 (Apr 2, 2010)

New in Firefox 3.5.9 (Mar 31, 2010)

New in Firefox 3.6.2 (Mar 23, 2010)

New in Firefox 3.7 Alpha 2 (Mar 3, 2010)

New in Firefox 3.0.18 (Feb 18, 2010)

New in Firefox 3.5.8 (Feb 17, 2010)

New in Firefox 3.7 Alpha 1 (Feb 10, 2010)

New in Firefox 3.6 RC2 (Jan 17, 2010)

New in Firefox 3.0.17 (Jan 5, 2010)

New in Firefox 3.0.16 (Dec 16, 2009)

New in Firefox 3.5.6 (Dec 16, 2009)

New in Firefox 3.6 Beta 4 (Nov 26, 2009)

New in Firefox 3.6 Beta 3 (Nov 18, 2009)

New in Firefox 3.6 Beta 2 (Nov 11, 2009)

New in Firefox 3.5.5 (Nov 6, 2009)

New in Firefox 3.6 Beta 1 (Oct 31, 2009)

New in Firefox 3.0.15 (Oct 28, 2009)

New in Firefox 3.5.4 (Oct 28, 2009)

New in Firefox 3.0.14 (Sep 10, 2009)

New in Firefox 3.5.3 (Sep 10, 2009)

New in Firefox 3.0.13 (Aug 4, 2009)

New in Firefox 3.5.2 (Aug 4, 2009)

New in Firefox 3.5.2 Build 1 Beta (Aug 3, 2009)

New in Firefox 3.0.12 (Jul 22, 2009)

New in Firefox 3.5.1 (Jul 17, 2009)

New in Firefox 3.5 RC2 (Jun 20, 2009)

New in Firefox 3.5 RC1 (Jun 17, 2009)

New in Firefox 3.5 Preview Beta 99 (Jun 11, 2009)

New in Firefox 3.0.11 (Jun 11, 2009)

New in Firefox 3.0.10 (Apr 28, 2009)

New in Firefox 3.5 Beta 4 (Apr 28, 2009)

New in Firefox 3.0.9 (Apr 21, 2009)

New in Firefox 3.0.8 (Mar 27, 2009)

New in Firefox 3.0.7 (Mar 4, 2009)

New in Firefox 3.0.6 (Feb 4, 2009)

New in Firefox 2.0.0.20 (Dec 19, 2008)

New in Firefox 3.0.5 (Dec 16, 2008)

New in Firefox 3.1 Beta 2 (Dec 9, 2008)

New in Firefox 3.1 Beta 1 (Dec 9, 2008)

New in Firefox 3.0.4 (Nov 12, 2008)

New in Firefox 3.0.3 (Sep 27, 2008)

New in Firefox 3.0.2 (Sep 24, 2008)

New in Firefox 2.0.0.17 (Sep 24, 2008)

New in Firefox 2.0.0.15 (Jul 2, 2008)

New in Firefox 3.0 (Jun 17, 2008)

One-click site info: Click the site favicon in the location bar to see who owns the site and to check if your connection is protected from eavesdropping. Identity verification is prominently displayed and easier to understand. When a site uses Extended Validation (EV) SSL certificates, the site favicon button will turn green and show the name of the company you're connected to.
Malware Protection: malware protection warns users when they arrive at sites which are known to install viruses, spyware, trojans or other malware.
New Web Forgery Protection page: the content of pages suspected as web forgeries is no longer shown.
New SSL error pages: clearer and stricter error pages are used when Firefox encounters an invalid SSL certificate.
Add-ons and Plugin version check: Firefox now automatically checks add-on and plugin versions and will disable older, insecure versions.
Secure add-on updates: to improve add-on update security, add-ons that provide updates in an insecure manner will be disabled.
Anti-virus integration: Firefox will inform anti-virus software when downloading executables.
Vista Parental Controls: Firefox now respects the Vista system-wide parental control setting for disabling file downloads.
Effective top-level domain (eTLD) service better restricts cookies and other restricted content to a single domain.
Better protection against cross-site JSON data leaks.
Easier password management: an information bar replaces the old password dialog so you can now save passwords after a successful login.
Simplified add-on installation: the add-ons whitelist has been removed making it possible to install extensions from third-party sites in fewer clicks.
New Download Manager: the revised download manager makes it much easier to locate downloaded files, and you can see and search on the name of the website where a file came from. Your active downloads and time remaining are always shown in the status bar as your files download.
Resumable downloading: users can now resume downloads after restarting the browser or resetting your network connection.
Full page zoom: from the View menu and via keyboard shortcuts, the new zooming feature lets you zoom in and out of entire pages, scaling the layout, text and images, or optionally only the text size. Your settings will be remembered whenever you return to the site.
Podcasts and Videocasts can be associated with your media playback tools.
Tab scrolling and quickmenu: tabs are easier to locate with the new tab scrolling and tab quickmenu.
Save what you were doing: Firefox will prompt users to save tabs on exit.
Optimized Open in Tabs behavior: opening a folder of bookmarks in tabs now appends the new tabs rather than overwriting.
Location and Search bar size can now be customized with a simple resizer item.
Text selection improvements: multiple text selections can be made with Ctrl/Cmd; double-click drag selects in "word-by-word" mode; triple-clicking selects a paragraph.
Find toolbar: the Find toolbar now opens with the current selection.
Plugin management: users can disable individual plugins in the Add-on Manager.
Integration with Windows: Firefox now has improved Windows icons, and uses native user interface widgets in the browser and in web forms.
Integration with the Mac: the new Firefox theme makes toolbars, icons, and other user interface elements look like a native OS X application. Firefox also uses OS X widgets and supports Growl for notifications of completed downloads and available updates. A combined back and forward control make it even easier to move between web pages.
Integration with Linux: Firefox's default icons, buttons, and menu styles now use the native GTK theme.
Star button: quickly add bookmarks from the location bar with a single click; a second click lets you file and tag them.
Tags: associate keywords with your bookmarks to sort them by topic.
Location bar & auto-complete: type in all or part of the title, tag or address of a page to see a list of matches from your history and bookmarks; a new display makes it easier to scan through the matching results and find that page you're looking for. Results are returned according to their frecency (a combination of frequency and recency of visits to that page) ensuring that you're seeing the most relevant matches. An adaptive learning algorithm further tunes the results to your patterns!
Smart Bookmarks Folder: quickly access your recently bookmarked and tagged pages, as well as your more frequently visited pages with the new smart bookmarks folder on your bookmark toolbar.
Places Organizer: view, organize and search through all of your bookmarks, tags, and browsing history with multiple views and smart folders to store your frequent searches. Create and restore full backups whenever you want.
Web-based protocol handlers: web applications, such as your favorite webmail provider, can now be used instead of desktop applications for handling mailto: links from other sites. Similar support is available for other protocols (Web applications will have to first enable this by registering as handlers with Firefox).
Download & Install Add-ons: the Add-ons Manager (Tools > Add-ons) can now be used to download and install a Firefox customization from the thousands of Add-ons available from our community add-ons website. When you first open the Add-ons Manager, a list of recommended Add-ons is shown.
Easy to use Download Actions: a new Applications preferences pane provides a better UI for configuring handlers for various file types and protocol schemes.
New graphics and font handling: new graphics and text rendering architectures in Gecko 1.9 provides rendering improvements in CSS, SVG as well as improved display of fonts with ligatures and complex scripts.
Color management: (set gfx.color_management.enabled on in about:config and restart the browser to enable.) Firefox can now adjust images with embedded color profiles.
Offline support: enables web applications to provide offline functionality (website authors must add support for offline browsing to their site for this feature to be available to users).
A more complete overview of Firefox 3 for developers is available for website and add-on developers.
Speed: improvements to our JavaScript engine as well as profile guided optimizations have resulted in continued improvements in performance. Compared to Firefox 2, web applications like Google Mail and Zoho Office run twice as fast in Firefox 3, and the popular SunSpider test from Apple shows improvements over previous releases.
Memory usage: Several new technologies work together to reduce the amount of memory used by Firefox 3 over a web browsing session. Memory cycles are broken and collected by an automated cycle collector, a new memory allocator reduces fragmentation, hundreds of leaks have been fixed, and caching strategies have been tuned.
Reliability: A user's bookmarks, history, cookies, and preferences are now stored in a transactionally secure database format which will prevent data loss even if their system crashes.