Firefox 146.0

Windows 10 users can now automatically protect their passwords, bookmarks, and more by turning on backup in Firefox. Your browsing data is saved daily on your device and can be encrypted with a password. When you set up a fresh install of Firefox on any operating system for a new device or your current one, you can restore from this backup and pick up right where you left off. This feature is currently available on Windows devices and will be coming to other operating systems soon. This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience.

MacOS users now have a dedicated GPU process by default. This includes WebGPU, WebGL, and Firefox's own WebRender. With this feature enabled, fatal errors in graphics code will no longer crash the browser, and will instead transparently restart the GPU process.

Firefox Labs is now available to all desktop users, regardless of whether they choose to participate in studies or submit telemetry. This means more experimental features are now available to more people.

Users can now skip the results page and see direct results as they type in the search bar for faster, simpler browsing. This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience.

There is a New Tab Weather opt-in workflow available for users in the EU and some other countries, where they can choose whether to enable location detection or manually search for a location. This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience.

Firefox now natively supports fractional scaled displays on Linux (Wayland), making rendering more effective.

For users of the English-language versions of Firefox in France, Germany, and Italy, the address bar now shows English-language suggestions for holidays and other important dates.

When the timepicker is enabled for <input type="time"> and <input type="datetime-local"> , it now provides full keyboard and assistive technology support. This update also improves the behavior of the time spin buttons for users who prefer reduced motion. The Firefox Accessibility team hopes that making the built-in timepicker accessible will encourage wider adoption of browser-provided time and date inputs across the web, reducing the need for custom controls, and improving accessibility for all users.

The Colors dialog in Settings now uses clearer color picker controls that keep each color sample next to its label. It makes it easier to understand and adjust text, background, and link colors when using a forced colors palette to customize the default text, link, and page background colors, especially with or without screen magnifiers.

Firefox removed support for Direct2D on Windows. If you still require Direct2D support, please use ESR 140.0 or higher.

On Windows, clicking tabs may not work at the very top of the screen when Firefox is maximized on a second monitor. We’re working to fix this in a future release. (Fixed in 147.0)

Various security fixes .

You can find information about policy updates and enterprise specific bug fixes in the Firefox for Enterprise 146 Release Notes .

Developer Information

Firefox now supports ML-KEM for WebRTC, by sending a post-quantum (PQ) key share during the DTLS 1.3 handshake. ML-KEM is the next-generation public-key cryptosystem that is believed to be secure against attackers with large quantum computers.

Firefox now supports compressed elliptic curve points in WebCrypto. These reduce the size of public keys by nearly half, saving bandwidth and storage, while still allowing the full point to be reconstructed mathematically.

The Skia graphics library has been updated to improve rendering performance and compatibility.

Unused CSS custom properties are now hidden by default in the Rule view of the Inspector. This not only reduces clutter, but in some cases also speeds up the rendering of the inspector panel.

With the release of Firefox 146, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 16 of whom were brand new volunteers! Please join us in thanking each of these diligent and enthusiastic individuals, and take a look at their contributions: Alex Johnson: 1924339

browsingData.removeLocalStorage and browsingData.remove (when localStorage is set in browsingData.DataTypeSet ) now delete objects from sessionStorage . ( Firefox bug 1886894 )

The proxy.onRequest API adds support for MASQUE proxies (proxy tunnel over QUIC) in the proxy.ProxyInfo return type. ( Firefox bug 1988988 and Firefox bug 1998894 )

<meta name="rating"> (Nightly): security.restrict_to_adults.always and security.restrict_to_adults.respect_platform The <meta name="rating"> element allows websites to self-identify as restricted/adult content. Browsers that recognize this element can then take steps to restrict users from viewing the content. See Restricting adult content with <meta name="rating"> for more details. ( Firefox bug 1991135 ).

Navigation API (Nightly): dom.navigation.webidl.enabled Nightly builds now support the Navigation API , which provides the ability to initiate, intercept, and manage browser navigation actions. It can also examine an application's history entries. This is a successor to previous web platform features such as the History API and window.location , which solves their shortcomings and is specifically aimed at the needs of single-page applications (SPAs) . ( Firefox bug 1979288 ).

Relative control points in CSS shape() curve commands : layout.css.basic-shape-shape.enabled You can use <relative-control-point> values when specifying a <curve-command> or <smooth-command> in a CSS shape() function. These values let you specify control points that are positioned relative to the start or end point of the current command, or relative to the origin (top-left) of the container the shape is being drawn inside.

The @scope rule is now supported, allowing authors to restrict styling to a subtree of the DOM. This avoids having to write overly-specific selectors.

Firefox now supports the contrast-color() CSS function that takes a color value and returns a contrasting color. Note that the specification currently restricts the contrasting color to black or white. This limitation is expected to be removed in the future. ( Learn more )

Introduced the text-decoration-inset property , which allows authors to adjust the start and end points of line decorations.

Firefox now supports the legacy -webkit-fill-available keyword as a value for the CSS width and height properties. This improves rendering of content on websites that use this value. This keyword is an alias for the recently standardized stretch keyword, which is not yet enabled in Firefox.

In the Rule view of the Inspector, when a displayed ruleset declares 10 or more CSS custom properties that are unused, those properties are hidden by default. This reduces clutter, and in some cases also speeds up the rendering of the Inspector panel. In such cases, the hidden properties can be displayed via a "Show..." button provided at the bottom of the ruleset. ( Firefox bug 1719461 ).

Operator mirroring in right-to-left (RTL) modes and stretching now work properly when used in combination. ( Firefox bug 1994172 ).

The math-shift property is now supported. This allows developers to indicate whether superscript rendering in MathML formulas should be normal or compact, affecting the height to which superscript text is shifted. ( Firefox bug 1994171 ).

The contrast-color() function is now supported. This function takes a <color> value and returns a contrasting color that ensures at least WCAG AA minimum contrast . ( Firefox bug 1682439 ).

The <color> data type now supports the display-p3-linear color space. This space is similar to display-p3 , except that it uses a linear-light transfer function and has no gamma-encoding, which allows for a higher precision in the colors displayed. ( Firefox bug 1996318 ).

The text-decoration-inset property is now supported, which enables adjusting the start and end points of an element's text-decoration so it can be shortened, lengthened, or have its position shifted with respect to the rendered text. ( Firefox bug 1979915 , Firefox bug 1997157 , Firefox bug 1993043 ).

The @scope at-rule is now supported by default. This enables you to select elements in specific DOM subtrees, targeting elements precisely without writing overly-specific selectors that are hard to override, and without coupling your selectors too tightly to the DOM structure. ( Firefox bug 1991105 ).

The legacy -webkit-fill-available keyword is now supported as a value for the CSS width and height properties to improve web compatibility. This keyword is an alias for the recently-standardized stretch keyword (i.e., width: stretch and height: stretch ), which isn't yet supported in Firefox. ( Firefox bug 1988938 , Firefox bug 1789477 ).

WeakMap and WeakSet now accept Symbol objects as keys, except for those that are registered . ( Firefox bug 1966745 ).

SubtleCrypto.importKey() now allows you to import keys defined as compressed elliptic curve points when using the ECDSA or ECDH algorithms. ( Firefox bug 1971499 ).

Updated the emulation.setLocaleOverride command to override the return value of navigator.language and navigator.languages alongside JS APIs. ( Firefox bug 1994396 ).

Updated the emulation.setLocaleOverride and emulation.setTimezoneOverride commands reset behavior to match recent specification changes. When calling this command to reset the override for a specific browsing context, overrides configured for a user context owning this browsing context will still apply. ( Firefox bug 1988725 ).

Added support for the context locator to the browsingContext.locateNodes command, which allows to retrieve the container of non-top-level browsing contexts, such as iframe elements. ( Firefox bug 1941270 ).

Implemented the network.setExtraHeaders command, which can be used to specify request headers which will be automatically added to requests triggered in the provided browsing contexts or user contexts. ( Firefox bug 1979731 ).

Updated all our network data collection commands ( network.addDataCollector , network.getData and network.disownData ) to support the request data type, which allows to collect and retrieve request post data. ( Firefox bug 1988955 ).

Improved our implementation for network.getData to also support requests using the data: scheme. ( Firefox bug 1992210 ).

Fixed a bug for network.getData which was not throwing the expected no such network data error for unsupported requests. ( Firefox bug 1992214 ).

Fixed a bug in our network events where different requests were reusing the same id, mostly impacting data URLs or cached requests. ( Firefox bug 1992348 ).

Fixed a regression in WebDriver:GetElementText that caused text containing accented characters (e.g., "ó") to be incorrectly capitalized. ( Firefox bug 1986392 ).

Fixed a bug in the WebFrame JSON deserialization that incorrectly raised a no such window error instead of no such frame when handling invalid frames. ( Firefox bug 1996540 ).

Added a WebDriver extension to control the Global Privacy Control signal. ( Firefox bug 1969865 ).