Fixed

• Various security fixes.

• Fixed an issue where certain parts of web pages, such as drop-down menus and specific styles, did not appear correctly when printing. (Bug 2026109)

• Fixed an issue where some website error pages displayed generic connection messages instead of the specific error code and description provided by the server. (Bug 2023800)

• Fixed a crash that occurred when using certain security keys or WebAuthn features for two-factor authentication. (Bug 2026688)

• Fixed an issue on Linux where the browser toolbar could become unresponsive to mouse clicks after dragging a tab when using Wayland. (Bug 2022238)

• Fixed a layout issue where text inside certain graphics (SVG) appeared shifted or misaligned from its intended position. (Bug 2024647)

• Fixed an issue where the "Send to device" option failed to work when used from the Open Tabs section in Firefox View. (Bug 2023201)

Enterprise

• Introduced a new enterprise policy that allows administrators to directly manage and control AI-related features within Firefox. (Bug 2019983)

• Fixed an issue where enterprise policies for the browser homepage and start page were not being applied correctly. (Bug 2027888)

• Introduced a new enterprise policy that allows administrators to prevent the built-in VPN and IP protection features from being available to users. (Bug 2022365)

• Reference link to 149.0 release notes.

New

• View two pages side-by-side in a single window with the new Split View feature that makes it easier to compare information, research topics or work across two pages at once. To create a split view, select one or two tabs and choose Add to Split View or Open in Split View.

  

• Firefox now offers a free built-in VPN. Whether you’re using public Wi-Fi while traveling, searching for sensitive health information, or shopping for something personal, this feature gives you a simple way to stay protected. Once you sign in and turn it on, you can hide your location and IP address by routing it through a secure proxy while you browse in Firefox. You will get 50 GB of protection every month, with the option to turn it on or off for specific websites. This feature is progressively rolling out in the US, UK, Germany and France starting today.

  

  Enterprise note: This feature is not available in enterprise environments and is not being rolled out to users with enterprise policies. While it can currently be enabled manually, administrators will have the ability to disable it via enterprise policy starting April 7. In the meantime, organizations can use the BlockAboutConfig policy to prevent manual enablement.

  

  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.

• Many PDF files will now load significantly faster thanks to hardware acceleration.

• Firefox now automatically blocks notifications and permanently revokes permissions for any website flagged as malicious by SafeBrowsing. This prevents unsafe sites from sending background notifications to users, commonly used for ads, spam or phishing.

• You can now add a Share button to your toolbar via Customize Toolbar, making it easy to share the current tab using your Windows or macOS system sharing options.

• Address Autofill is enabled for users in Australia, India, Italy, Poland and Austria.

• Explore more of the web with new on-device translation support for Bosnian, Norwegian Bokmål, Serbian and Thai — plus improved accuracy for Croatian.

Firefox Labs

• Tab notes feature that lets you attach a short note to a web page is now available in Firefox Labs. You can use notes to remember why you opened a page, what you planned to do next or any details you want to revisit later. Please give notes a try and share your feedback on what works well and what can be improved.

  

Fixed

• Increased robustness of HTTP/3 upload performance for unstable network conditions.

• Various security fixes.

Changed

• The TrustPanel combines the privacy and security panels accessed from the address bar to give the user one place to check the Privacy and Security settings of the current page. Learn more.

  

• Security has been strengthened by tightening the requirements for JavaScript files that can be loaded in the parent process, providing additional defense in depth against potential threats.

• On Linux, Firefox will now default to the XDG portal file picker if available, rather than the GTK3 one, which is usually better integrated with the user's desktop environment, and more powerful.

• Firefox error pages have a fresh new look, with updated visuals that better match the overall feel of Firefox. The redesigned pages create a more cohesive experience while making it clearer what went wrong.

  

• On Windows, Firefox will use the modern Windows.Devices.Geolocation API for geolocation instead of Windows 7 location API.

Developer

• Developer Information

• The toolbar of the Storage Inspector now has a button to delete all entries of the currently selected storage.

• Besides each CSS declaration related to a computed value shown in the Computed view there's now an icon to jump to it in the Rules view.

Web Platform

• showPicker() now supports text-based <input> elements with an associated <datalist>, displaying the autofill dropdown. See documentation.

• The functions xywh() and rect() were previously implemented for the clip-path and offset-path properties. They are now also available for the shape-outside property.

• The math value of the CSS font-family is now supported and used by default for MathML's <math> element. It enables Web developers to indicate special fonts with advanced math features should be used. Firefox will rely on the serif font for mathematics defined in Firefox preferences.

• Added support for the HTML attribute popover="hint".

• Enabled media element pseudo-classes, such as :playing, :paused…

• Enabled the spec-compliant HTMLMediaElement.captureStream() API.

• Added support for closing popovers & dialogs with the Android Back Button, and implemented the CloseWatcher API for handling this in script.

• The new Reporting API provides a generic reporting mechanism for web applications to use to make reports available based on various platform features (for example Content Security Policy, Permissions-Policy or feature deprecation reports) in a consistent manner.

Community Contributions

• With the release of Firefox 149, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 25 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:

  • aaryamannsingh3: 1968250
  • Alex Leykin [:alexff]: 1989707
  • César Pedraza [:cpedraza]: 1933577
  • Daniel Tang: 2012556
  • Denys [:denyshon]: 1768757, 1804855, 1975076, 2010370, 2010914
  • felix: 2008777
  • Franccesco: 1984274
  • Gregor Dschung [:chkpnt]: 2004881
  • Henry Yeary: 1944835, 2010907
  • Jacob: 2014579
  • kian: 1643915
  • lucrobertvillanueva: 1988103
  • Matt M: 2012236
  • MUTHUSRIHEMADHARSHINI: 1994079
  • Nishchay [:nish]: 1945967
  • Ranvir Sahota: 1884983
  • Seva Alipov: 2000120
  • Simon: 1973209
  • Thomas Sileo: 1623654, 2011537
  • torrenceb90: 2003192
  • Tyler Thrailkill [:snowe]: 2003187, 2012756, 2013500
  • vadimhack.ru: 2016172
  • yooughtul: 1944213
  • Yung Kai [:YuK]: 2011420
  • Yvon Cognard: 1953375

Fixed

• Fixed an issue where searches entered in the Firefox Home search field were incorrectly redirected to the address bar for some users who had disabled search handoff behavior via advanced settings. (Bug 2017049)

• Fixed an issue where some web-based rich text editors stopped applying formatting, such as bold or italic. (Bug 2020927)

• Fixed an issue where videos could autoplay unexpectedly on YouTube despite autoplay being blocked, particularly impacting screen reader users. (Bug 2020233)

• Fixed an issue that caused some absolutely positioned elements meant to be centered, for example, using margin: auto with inset: 0, to appear left-aligned on initial load. (Bug 2017440)

• Fixed an issue where the “Switch to Tab” suggestion in the address bar appeared blank for pages without a title. (Bug 2020341)

• Fixed an issue that could reduce video quality on Windows systems using NVIDIA GPUs with Video Super Resolution enabled. (Bug 2019515)

• Various security fixes.

• Reference link to 148.0 release notes.

New

• Added an AI Controls section to Settings for managing AI-enhanced features. Learn more.

  

• Firefox now has improved support for screen readers accessing mathematical formulas embedded in PDFs.

• Remote improvements are now decoupled from telemetry requirements in Firefox Settings. You can now opt into receiving remote browser changes even if you have opted out of sharing telemetry or participating in our experimental studies.

• Firefox Backup is now available on Windows 10 to users who also use the “Clear history when Firefox closes” capability. Backups will not include any data which is set to be cleared when Firefox is closed.

• The following languages are now available for translation:

  • Translation into and from Traditional Chinese.
  • Translation into Vietnamese.

• New Tab wallpapers will now appear on new container tabs as well as new default tabs.

Fixed

• Fixed an issue where a language pack could become disabled after a major update, causing Firefox to display in the wrong language.

• On Windows, dragging a downloaded image to Adobe Illustrator now correctly inserts the image instead of its URL.

• Various security fixes.

Developer

• Developer Information

Web Platform

• The initial about:blank document is now Web-compatible. If the first navigation of a browsing context goes to about:blank, it completes synchronously and is no longer replaced by a second parser-generated document.

• Service worker support for WebGPU has been added, making it available in all worker contexts. Service workers allow WebGPU to run in the background, which is particularly useful for extensions and other pages that can meaningfully share resources across multiple tabs and time periods.

• Firefox now supports the Iterator.zip() and Iterator.zipKeyed() methods from the joint iteration proposal. This allows zipping together underlying iterators into an iterator over values grouped by position, similar to zip in many other languages.

• Firefox now supports the Trusted Types API, which is primarily aimed at preventing cross-site scripting attacks.

• Firefox now supports the Sanitizer API, which provides new methods for HTML manipulation. The element.setHTML() method enables developers to insert HTML content similarly to element.innerHTML, but without the security vulnerabilities such as cross-site scripting (XSS). A complementary method, document.parseHTML(), is also available for parsing HTML safely.

• Firefox now supports the location.ancestorOrigins attribute.

• Firefox now supports the NavigationPrecommitController.addHandler() interface of the Navigation API. This allows registering a post-commit navigation handler during the pre-commit phase, to allow a multi-step navigation process.

• Firefox now supports the position-try-order property as part of CSS Anchor Positioning, controlling the order of fallback positioning attempts.

• Firefox now supports the CSS shape() function, which allows defining responsive free-form shapes in properties that take shapes like clip-path. Unlike path(), it uses standard CSS syntax, supports various CSS units, and allows mathematical functions.

Community Contributions

• With the release of Firefox 148, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 18 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:

  • Charlotte Wilson [:cswilson252]: 1774438
  • Doğu Abaris: 2006856
  • Ethan Hawksley: 2008109
  • Johannes Odland: 2005934
  • kentaro tachikawa: 1819853
  • Kiril Panayotov: 2001615
  • Matt Kwee: 1938752
  • Nathan: 2004797
  • Noriaki Watanabe: 2004688, 2005964, 2006047, 2006777, 2007503, 2008007, 2008072, 2008282
  • Rachel Rusiecki: 1804921
  • Rocco Jiang: 2008967
  • Sameem [:sameembaba]: 1976416
  • Serah Nderi: 1306461, 2007291
  • Sergey Radionov: 1976489
  • valadaptive: 1983387
  • Vignesh Sadankae: 2003183
  • Will Medina [:willyelm]: 2003345
  • Yunju Lee: 1987021, 2003165, 2004209, 2004268

New

• Firefox now allows you to customize your keyboard shortcuts to replace hard-to-type or hard-to-remember hotkeys, eliminate conflicts with other software, and create your preferred set. Access this experimental new feature by typing about:keyboard in the address bar and please share your feedback with us on Mozilla Connect!

Fixed

• Resolved various issues with missing or impaired browser functionality when using XDG Base Directories on Linux. (Bug 2011300)

• Fixed an issue causing excess passkey prompts to appear when logging into some sites. (Bug 2010919)

• Fixed an issue that could lead to sites being incorrectly flagged as malicious by SafeBrowsing. (Bug 2010956)

• Various security fixes.

• Reference link to 147.0.1 release notes.

Fixed

• Fixed compatibility problems with websites that use the new Compression Dictionaries technology, such as ChatGPT, by temporarily disabling the feature. (Bug 2010712)

• Fixed an issue where an unnecessary empty directory was created on Linux systems. (Bug 2001887)

• Fixed an issue where time formats could cause certain websites to display incorrectly. (Bug 2010411)

• Reference link to 147.0 release notes.

New

• Address autofill has been enabled for users in Switzerland.

• WebGPU support is now enabled for devices with Apple Silicon processors on all supported macOS versions.

• Improved video playback performance on systems with AMD GPUs by enabling zero-copy playback for hardware-decoded video where supported, bringing them to parity with Intel and NVIDIA GPUs.

• Firefox now supports the Safe Browsing V5 protocol and is migrating from Safe Browsing V4 to the local list mode of Safe Browsing V5 protocol.

• Users with Enhanced Tracking Protection (ETP) set to Strict will have local network access restrictions enabled by default. Firefox will now require users to explicitly allow public websites to access local network resources.

  

  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 allows you to customize your keyboard shortcuts to replace hard-to-type or hard-to-remember hotkeys, eliminate conflicts with other software, and create your preferred set. Access this experimental new feature by typing about:keyboard in the address bar and please share your feedback with us on Mozilla Connect!

• Firefox now supports the Freedesktop.org XDG Base Directory Specification.

• A Picture-in-Picture player window can now optionally be opened automatically for a video playing in a tab when that tab goes into the background. A special thanks to volunteer Daniele Ferla for contributing this feature!

  

Fixed

• Fixed an issue that prevented some Windows users from selecting a tab when the cursor was at the top of the screen and the Firefox window was maximized.

• Fixed a bug that made HTTP/3 requests containing non-UTF-8 header values time out or fall back to HTTP/2 after a while.

• A draggable button can now be dragged if initiated from the button itself.

• For Linux GNOME Mutter users, window and rendering surface sizes were updated to match the actual pixel grid so Firefox delivers sharp rendering on fractionally scaled displays regardless of the actual window size.

• Various security fixes.

Changed

• Firefox now uses the same quality values (q-values) in Accept-Language headers as other major browsers. The second language preference is now sent as q=0.9 instead of q=0.5, with subsequent language preferences decreasing by 0.1 each (minimum 0.1). This change fixes compatibility issues with some servers that incorrectly rejected requests with lower quality values.

Enterprise

• You can find information about policy updates and enterprise-specific bug fixes in the Firefox for Enterprise 147 Release Notes.

Developer

• Developer Information

• View Transitions: View transition pseudo-elements now appear in the elements panel and the associated animations appear in the animations panel.

• Anchor positioning: Elements with a valid anchor-name are given an 'anchor' badge in the elements view, and @position-try CSS rules are now displayed in the CSS rules panel when an element using position-try-fallbacks is selected.

• The JSON viewer now has a button to import the resource into Firefox Profiler to get a breakdown of its size.

• Pseudo-element selectors can now be added/edited in the CSS rules panel.

Web Platform

• Added support for the Navigation API. This API provides the ability to initiate, intercept, and manage browser navigation actions. It is a successor to previous web platform features such as the History API and window.location, which solves their shortcomings.

• The Unicode ICU library was updated to release 78, bringing support for Unicode 17 and new locales.

• ES modules in service workers are now supported, aligning Firefox with other major browsers and improving compatibility for modern web apps.

• Support for CSS Module Scripts was added, allowing stylesheets to be imported using the JavaScript module system and import attributes.

• The CSS counter-* and quotes properties are now supported in the ::marker pseudo-element.

• Both CompressionStream and DecompressionStream now support the Brotli format.

• Firefox now supports the :active-view-transition-type selector and associated View Transitions API changes.

• Firefox now exposes the view transition currently active on the document via the Document.activeViewTransition property.

• Support for CSS anchor positioning was added, enabling tethering elements. The anchor-positioned elements can then have their size and position set relative to the anchor elements to which they are bound.

• Firefox now supports Storage-Access-Headers, allowing servers to opt into unpartitioned cookies via HTTP headers if storage-access was granted prior to the Storage Access API.

• Implemented CSS root-font-relative units rcap, rch, rex and ric.

Community

• With the release of Firefox 147, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 14 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:

  • [:Joe Cardoso] Loan de Deus Vieira Cardoso: 1730474, 1897620
  • Aaron Kriegman: 1955625
  • Aloys: 2002985, 2003194
  • Areeba: 2000792
  • Daniel Singer: 1895228, 1981571
  • Dominique: 1995325, 2000957
  • James Hay: 1864284
  • Kipchumba Chelilim [:mrchumbastic]: 1905323, 1956817, 1994752
  • Lorenz A: 983296, 1632071, 1665702, 1709063, 2004038, 2004205
  • Michal Bozon: 1998963
  • Scott Venkataraman: 1995324, 1999325
  • Sick Leviathan: 1362499, 1918733, 1960699
  • Tom Forbes: 1897424
  • witty.31.06: 2000613, 2000765

Fixed

• Improved overall stability by fixing crashes related to browsing, graphics, and accessibility features. (Bugs 2001160, 1998185, 1998188)

• Fixed an issue where fingerprinting protection caused incorrect font rendering on popular websites. (Bug 2000429)

• Fixed crashes related to media playback and GMP process shutdown. (Bug 2002697)

• Fixed an issue where desktop profile shortcuts were being unintentionally removed when changing copied profile settings. (Bug 1998209)

• Improved sidebar text contrast when using vertical tabs with certain themes. (Bug 2006091)

• When restoring from a backup, the restore success message will appear over the new tab page instead of one of the tabs restored from a backup, to avoid cases where the restored tab canceled the restore success message. (Bug 2003307)

• Various security fixes.

• Reference link to 146.0 release notes.

Unresolved

• 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)

New

• 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.

Fixed

• 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.

• Various security fixes.

Changed

• 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.

Enterprise

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

Developer

• 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.

Web Platform

• 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.

Unresolved

• 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)

Community Contributions

• 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
  • Apurva: 1973318
  • Cornelius Emase: 1913086, 1977921, 1996578, 1996859, 1998012
  • Ethan Gallucci: 1991983
  • gopi: 1940198
  • Jeffrey Houghton: 1900302
  • Julian: 1945449
  • Leonardo Paffi: 1996678
  • Loago Zambe: 1975592
  • Meg Ford: 1898383, 1997187
  • Mingyuan Zhao [:MagentaManifold]: 1995168
  • Pavel Kireev: 400264, 1852625, 1975612, 1986459, 1988355, 1998237
  • PhuongNam: 1968398
  • Simon Knott: 1993703
  • Thomas J Faughnan Jr: 1994098
  • zzjas98: 1997216

Fixed

• Fixed an issue that prevented typing in Baidu’s search box when using Chinese IMEs on Windows. (Bug 2000479)

• Reference link to 145.0.1 release notes.

Unresolved

• 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)

Fixed

• Fixed an issue causing breakage on sites using Three.js. (Bug 1995939)

• Fixed a failure to open Firefox from the desktop launcher on older versions of Windows 10. (Bug 2000411)

• Fixed Web compatibility issues with Rogers. Rogers customers would see a broken iframe with "Firefox Can’t Open This Page" when viewing bills, rather than the billing info. (Bug 1996823)

• Fixed an issue in the Web Developer Tools preventing copy all or save all requests as HAR. (Bug 1995694)

• Reference link to 145.0 release notes.

Unresolved

• 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)

New

• Add, edit, and delete comments to make your own notes in PDFs (summaries, questions, tasks, etc.). The comment sidebar helps you scan all your comments and quickly jump to them, which is handy for long or heavily marked-up PDFs.

  

• This version introduces a new phase of privacy protections, building on our research on reducing browser fingerprinting. These new defenses cut the percentage of users seen as unique almost in half, ensuring a safer and more private browsing experience in Private Browsing or when using Enhanced Tracking Protection set to Strict.

• Need a reminder of what tabs are in a group? Hover over the tab group name to get a preview of the tabs inside without opening it.

• You can now access and manage your saved passwords right from the sidebar—no need to open a new tab or window. Stay on the page you’re on and get to your logins faster.

  

• Copy Link to Highlight allows users to share arbitrary sections of a page with others by copying a link through the context menu with a given selection

• The Translations feature has an improved experience when translating between languages with different script directions.

• New brand-inspired wallpapers are available for New Tab on desktop, with versions for both light and dark mode.

• With the new Open links from apps next to your active tab setting, you can have links from other applications open next to your active tab instead of at the end of the tab strip.

  

• Enhanced Bounce Tracking Protection’s stateless mode is now enabled by default in ETP Strict, blocking more advanced tracking techniques based on redirection

• For most Windows users, the existing desktop shortcut for launching Firefox has been replaced with the desktop launcher, a small program that will launch Firefox if it is installed, but if it is not installed will prompt the user to install Firefox. This will provide an easy installation point for Firefox users who acquire a new Windows device, where Firefox will not be installed by default, but the desktop launcher program may have synced via OneDrive or other cloud storage product. Learn more.

  

Fixed

• Various security fixes.

Changed

• Firefox no longer supports 32-bit Linux systems. We recommend installing the 64-bit version for continued updates and support.

• Horizontal tabs are now slightly more rounded to match the look of vertical tabs. Buttons and text inputs, including the address bar, have also been updated for consistency.

• When no extensions are installed, clicking the Extensions button now shows a message highlighting how extensions can enhance your browsing, with links to the Firefox Add-ons store.

• Local translation models are now compressed with Zstandard, reducing download sizes and on-device storage consumption. As always, all Firefox translations happen securely and privately on your local device, unlike other browsers that translate using cloud services.

• We updated default automation preferences to better support Agentic browsing, reducing the steps agents need to complete a task and chances for the agent to get stuck.

Enterprise

• You can find information about policy updates and enterprise specific bug fixes in the Firefox for Enterprise 145 Release Notes.

Developer

• Developer Information

• Microsoft UI Automation phased release rollout at 100%. Microsoft UI Automation is the new accessibility framework for Microsoft Windows. This will provide better assistive technology (AT) support and performance on Windows for current and future assistive technologies.

Web Platform

• Support has been added for the Atomics.waitAsync proposal, which is a non-blocking, asynchronous version of Atomics.wait. This allow synchronization of threads based upon the value in a shared memory location, for more details please consult our MDN documentation.

• Firefox now supports the new Integrity-Policy header for enforcing sub-resource integrity for scripts. Further implementation of this header is underway.

• Added Matroska support for the most commonly used codecs: AVC, HEVC, VP8, VP9, AV1, AAC, Opus, and Vorbis.

• The text-autospace property is now supported, allowing automatic spacing adjustments between characters from different scripts.

• The WebGPU DOM API (spec; MDN) is now available on macOS 26 (Tahoe) on Apple Silicon. For details, see the Mozilla Graphics Team Blog.

Unresolved

• 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)

Community Contributions

• With the release of Firefox 145, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 5 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 Hill: 627771
  • Khalid AlHaddad: 1882718, 1975161
  • Kyler Riggs [:kylr]: 1955241, 1974265
  • Mag Mukendi: 1982207
  • Mateo Mihm: 1957059
  • Tatsunori Uchino: 1950321
  • Vlad L: 1881524

Fixed

• Fixed an issue where the list of available locales in about:settings contained more locales than were downloaded or currently supported. (Bug 1994642)

• Fixed an issue where using the keyboard to open the Unified Search dropdown was inconsistent. The dropdown now expands properly, allowing users to select a search engine using the keyboard. (Bug 1979826)

• Fixed an issue where curated photo collections on Microsoft OneDrive's Photos “For You” page failed to load, showing a gray screen instead of content. Collections now display as expected. (Bug 1986533)

• Fixed a startup crash affecting Windows users with Avast or other security software installed. (Bug 1992678)

• Fixed an issue on macOS where the emoji picker shortcut and menu entry stopped working after switching between apps. (Bug 1980815)

• Fixed an issue on macOS where dragging images from Firefox into third-party apps like Preview could fail or behave unexpectedly. (Bug 1995345)

• Fixed performance and video playback issues on macOS 26 (Tahoe) that occurred when the system was under heavy load. (Bug 1995638)

• Fixed a browser hang on macOS 26 (Tahoe) that could occur when bookmark folders contained loops or repeated references to themselves. (Bug 1995621)

• Security fix.

• Reference link to 144.0 release notes.

New

• Focus on just one tab in a group without the clutter. Your active tab now stays in view, keeping things tidy even with the group collapsed.

  

• We’re excited to share another tab groups update that addresses a top request from our community! You can now drag a tab into a collapsed group without automatically expanding it. It’s a quick way to stay organized while minimizing visual distractions.

• Profile management, now rolling out gradually to users globally over the next few weeks, helps you protect your privacy and stay focused by separating your online life into distinct profiles for work, school, vacation planning, or whatever you choose. You can name your profiles and customize them with avatars and color themes for easy recognition, then quickly switch between them while keeping bookmarks, tabs, and browsing history completely separate. The new Profiles feature is available for Windows 11, Mac, and Linux users, with Windows 10 support coming 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.

• You can now close a Picture-in-Picture window without pausing the video. Press Shift + Click on the close button or use Shift + Esc to exit while keeping playback uninterrupted.

• Logins stored in the Firefox Password Manager are now encrypted on disk using a modern encryption scheme (AES-256-CBC), replacing the older 3DES-CBC. This change improves local data protection. Logins synced through Firefox Sync remain end-to-end encrypted and already use AES-256-GCM.

• Visual search powered by Google Lens

  With just a right-click on any image, you can now:
  ✨ Find similar products, places, or objects
  ✨ Copy, translate, or search text from images
  ✨ Get inspiration for learning, travel, or shopping

  Look for the new “Search Image with Google Lens” option in your right-click menu (highlighted with a NEW badge at first).
  This is a desktop-only feature, rolling out worldwide. Your default search engine must be set to Google in order to use it.

  

  

  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.

• Perplexity AI Search in Firefox

  On desktop, Firefox now includes Perplexity, an AI-powered answer engine built into the browser. Perplexity delivers direct, conversational answers to complex questions, helping you get quick summaries, accurate references, or creative inspiration without digging through multiple sources. It’s rolling out worldwide from the address bar via the unified search button.

  

  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.

• The following languages are now available for translation:

  • Azerbaijani
  • Bangla
  • Icelandic

Fixed

• Various security fixes.

• The following languages have improved translation quality:

  • Arabic
  • Bulgarian
  • Catalan
  • Chinese (Simplified)
  • Czech
  • Dutch
  • Estonian
  • Finnish
  • French
  • German
  • Hungarian
  • Italian
  • Japanese
  • Portuguese
  • Persian
  • Spanish
  • Ukrainian

Changed

• On Windows, when opening a link from another application, Firefox will only use a window on the current virtual desktop or open a new window if needed.

Enterprise

• You can find information about policy updates and enterprise specific bug fixes in the Firefox for Enterprise 144 Release Notes.

Developer

• Developer Information

• You can now jump to a CSS custom property's definition from within the var() function in style rules.

• The events tooltip in the Inspector now shows a badge besides custom events, making it easier to differentiate them from built-in events.

Web Platform

• Firefox now supports the Element.moveBefore API.

• Firefox now supports math-shift compact.

• Firefox now supports PerformanceEventTiming.interactionId, allowing developers to group related input events. This enables support for the Interaction to Next Paint (INP) responsiveness metric.

• Firefox now supports the command and commandfor attributes.

• Firefox now supports the View Transitions API Level 1. The View Transitions API provides a mechanism for easily creating animated transitions between different website views.

• Dithering is now applied when linear-gradient, conic-gradient, and radial-gradient are rendered using hardware WebRender.

• Firefox now supports the upsert proposal. This adds getOrInsert and getOrInsertComputed methods to Map and WeakMap. These methods either return the value associated with a key, or insert a default value, and then return that value, simplifying handling of cases where it's not known if a key is already present in the Map or WeakMap.

• Firefox now supports the lock() and unlock() methods of ScreenOrientation interface on Windows tablets and Android devices.

• Firefox now supports worker transfer for RTCDataChannel.

• Firefox now supports the resizeMode getUserMedia constraint, allowing developers to crop and downscale video captured from a camera to any resolution they choose.

• Firefox now supports the WebGPU GPUDevice.importExternalTexture API on Windows.

• WebCodecs on Windows now has a batch-encoding path for VideoEncoder, improving performance with higher throughput and lower submission latency due to a larger default batch size.

• Gecko-specific CSS2Properties was renamed to CSSStyleProperties, to align with the latest web standard and for better interoperability with other browser engines.

Community Contributions

• With the release of Firefox 144, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 12 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:

  • Alice Boxhall: 1981341
  • David [:david-loe]: 1726108
  • Diogo Sousa: 1987258
  • fdangers: 1975105
  • jocelyne.ah1: 1980995
  • Josh Berry: 1984553
  • Martin Bruse: 1987128
  • Mountain Dude: 1984695
  • parisoplop: 1984782
  • Riz: 1280266
  • s175911: 1985163

Fixed

• Adjusted the timing of the new drag-to-pin interaction cue for better reliability. (Bug 1989344)

• Fixed an issue that prevented some extensions from updating via the Add-ons Manager. (Bug 1984724)

• Fixed a regression that prevented Firefox View sections from collapsing/expanding as expected. (Bug 1989200)

• Addressed a WebExtensions storage issue that could cause Firefox to crash on startup with certain extensions installed. (Bug 1989840)

• Fixed an issue where opening an add-on's "Extension settings" from the post-install prompt could break the Customize tab and some keyboard shortcuts until restart. (Bug 1983869)

• Reduced long delays when loading certain websites while connected to networks that block UDP connections. (Bug 1980812)

• Various stability and security fixes.

• Reference link to 143.0.1 release notes.

Fixed

• Fixed a tab crash experienced by some users caused by DLL injection. (Bug 1872261)

• Reference link to 143.0 release notes.

New

• On Windows, Firefox now supports running websites as web apps pinned directly to the taskbar. These are sites that you can pin and run as simplified windows directly from the taskbar without losing access to your installed add-ons. This feature is not currently available for Firefox installs from the Microsoft Store.

• Tabs can now be pinned by dragging them to the start of the tab strip, making it easier to keep important sites within reach.

  

• Copilot from Microsoft can now be chosen as a chatbot to use in the sidebar for quick access without leaving your main view.

• When a site asks for camera access, it can now be previewed inside the permission dialog. This is especially helpful when switching between multiple cameras.

  

• The Firefox address bar can now show you important dates and events. This feature supports displaying events (e.g. “Mother’s Day”) in the United States, United Kingdom, Germany, France, and Italy regions.

• Firefox has expanded its Fingerprinting Protection by reporting constant values for several more attributes of user's computers.

• When downloading a file in Private Browsing mode, Firefox now asks whether to keep or delete it after that session ends. You can adjust this behavior in Settings.

  
  

• Firefox now supports Windows UI Automation, which improves support for accessibility tools such as Windows Voice Access, Text Cursor Indicator and Narrator.

  

  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.

Fixed

• Various security fixes.

Enterprise

• You can find information about policy updates and enterprise specific bug fixes in the Firefox for Enterprise 143 Release Notes.

Developer

• Developer Information

• Unchecking the Group Similar Messages setting now prevents successive similar messages from being grouped so that all messages are displayed in the output.

• Switching between unmodified and pretty printed sources in the debugger no longer opens a new tab for pretty printed content.

• When the Inspector is focused, the eyedropper can now be launched to pick a color via the Ctrl+Shift+Y keyboard shortcut.

Web Platform

• Firefox now supports xHE-AAC audio playback on Windows 11 22H2+, macOS, and Android 9+.

• Firefox now uses an updated grid sizing algorithm to better align with the CSS Grid specification. Grid layouts that use percentage row sizes or grid items containing elements with aspect ratios (such as images) will now render correctly in more cases.

• <input type=color> now recognizes the CSS <color> format in addition to the color hex format (#ffffff). This means that color names like black and more complex strings like rgb(200 200 200) are now valid inputs. For now the value will always be converted to the hex format.

• Restrictions were removed that prevented setting the display property on <details> elements, and a ::details-content pseudo-element was added to style the expandable/collapsible contents of those elements.

Community Contributions

• With the release of Firefox 143, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 12 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:

  • AnonAlly: 1978245
  • Balraj Dhawan: 1977903
  • Damia Vergnet: 1932365, 1979629
  • Gaétan Fine: 1177108
  • jonas.muecke: 1978226
  • Markus Probst: 1976974
  • Mason Abbruzzese: 1957214
  • Mauro V [:cheff]: 1507381, 1849937, 1872780, 1938638, 1943057, 1975093, 1976968
  • Nicolas Auvray [:Itms]: 1982134
  • overflowcat: 1978108
  • Robert: 1980791
  • s1m: 1964526

Fixed

• Dragging multiple non-adjacent tabs in horizontal tab strip mode now correctly moves them together as a group. (Bug 1982933)

• Dragging multiple tabs no longer causes toolbar unresponsiveness or visual glitches. (Bug 1984342)

• Fixed an issue where the text cursor appeared in the wrong location.. (Bug 1984045)

• Fixed a crash related to gamepad use, particularly on macOS. (Bug 1870379)

• Fixed an issue where the expand on hover feature in the sidebar would sometimes stop working. (Bug 1982129)

• Fixed a crash in KDE Plasma when using certain custom window decorations. (Bug 1984823)

• Reference link to 142.0 release notes.

New

• For users in the United States, article recommendations on your New Tab page are now grouped into topic sections like Sports, Food, and Entertainment to make stories more organized and easier to scan. You can also follow topics you’re interested in and block ones you’d prefer not to see, giving you more control over what shows up when you open a new tab.

  

  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.

• You can now see what’s behind a link before visiting it with Link Previews. Long press a link (or right-click and choose Preview Link). Previews can optionally include AI-generated key points, which are processed on your device to protect your privacy.

  Link Previews is gradually rolling out to ensure performance and quality and is now available in en-US, en-CA, en-GB, en-AU for users with more than 3 GB of available RAM.

  

  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.

• On Windows, clicking a persistent notification when Firefox is closed or restarted will now properly open Firefox with the relevant webpage, instead of just opening the main page of the website.

• ETP Strict mode now supports a flexible exception list to fix broken site features caused by tracker blocking. Exceptions are split into baseline (core functionality) and convenience (extra features), letting users choose improved site compatibility without compromising key privacy protections.

• Keep an active tab visible in a collapsed tab group
  Focus on just one tab in a group without the clutter. Your active tab stays in view, keeping things tidy even with the group collapsed.

• You can now remove extensions from the sidebar by right-clicking the extension icon and selecting Remove from Sidebar.

Fixed

• Improved the scroll speed in the bookmarks dialog to not go beyond the component area.

• Improved drag-and-drop support for blob images.

• Various security fixes.

Changed

• Improved search results from browsing history via the address bar, reducing the likelihood of duplicate results being shown.

• Improved Netmonitor so that Request Headers/Cookies/Params are displayed in the Network panel even if the request isn't finished yet.

Enterprise

• You can find information about policy updates and enterprise-specific bug fixes in the Firefox for Enterprise 142 Release Notes.

Developer

• Developer Information

• Firefox now supports the wllama API for extensions, enabling developers to integrate local language model (LLM) capabilities directly into their add-ons.

• The Debugger now offers a new setting to control whether the debugger overlay is shown during paused script execution.

  

• Firefox now supports the Prioritized Task Scheduling API, enabling developers to assign and manage task priorities.

• The Selection.getComposedRanges() API is now available, allowing developers to accurately get selected text ranges across shadow DOM boundaries.

• Added support for the URLPattern API, enabling developers to match and parse URLs using a standardized pattern syntax.

Unresolved

• Multiselecting non-contiguous tabs to drag may result in toolbar unresponsiveness or visual glitches. Dragging any single tab should resolve this. We will be landing a fix in the next dot release with Bug 1984342.

Community Contributions

• With the release of Firefox 142, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 20 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 Stout: 1845523
  • Ayush Kaintura: 1963306
  • Beatriz Rizental: 1971306, 1972755
  • biyul.dev: 1931528, 1975074, 1976504
  • celenity: 1977078
  • chase.philpot: 1973697
  • Clément Brisset: 1969603
  • Connor Sabine: 1975559
  • eri: 1958853
  • Ernest Molner: 1968300
  • Jacqueline Amherst: 1961204
  • jesper: 1974023
  • Jim Gong: 1975871
  • JP Belval: 1961487
  • jtech3029: 1951724
  • Nate Gross: 1957261, 1968719
  • Richard LoRicco: 1975300
  • Rong Bao [:csmantle]: 1975201, 1975350, 1975439, 1975492, 1975643, 1975645, 1975720, 1975752, 1975849, 1975983, 1976155, 1976157, 1976225, 1976389, 1976397, 1976410, 1976699, 1976799
  • shwetank.tewari.87: 1831397
  • William: 1960743

New

• Now Firefox can help you keep your tabs organized, automatically. A local AI model identifies similar tabs, automatically organizes them into groups, and even suggests group names. Everything happens on your device to respect your privacy. Learn more here.

  

  

  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.

• Vertical tabs users can now adjust the size of the tools areas at the bottom of the sidebar. To see fewer tools and more tabs, drag down the divider line which pushes extra tools into an overflow menu.

  

• On Linux, Firefox uses less memory and no longer requires a forced restart after an update has been applied by a package manager.

• Address autofill has been enabled for users in Brazil, Spain and Japan.

• The Firefox address bar can now be used as a unit converter. The unit converter supports converting units of length, temperature, mass, force, and angular measurement, as well as timezones (e.g. “now in GMT” , “10am EDT to CET”). Selecting the result will copy it to your clipboard. Learn more here.

  

• Firefox builds in Valencian now come with a built-in Catalan (Valencian variant) dictionary for the Firefox spellchecker.

• The following languages are now available for translation:

  • Albanian
  • Gujarati
  • Hebrew
  • Hindi
  • Kannada
  • Malay
  • Malayalam
  • Persian
  • Telugu

Fixed

• Various security fixes.

Changed

• Firefox on Windows 11 now uses system provided font icons for the caption buttons, more in line with Windows 11 conventions.

Enterprise

• You can find information about policy updates and enterprise specific bug fixes in the Firefox for Enterprise 141 Release Notes.

Developer

• Developer Information

• Firefox will now also clear the back-forward-cache when receiving the Clear-Site-Data: "cache" response header.

• When creating a logpoint in the Debugger, there's now a checkbox allowing to output the stacktrace in addition to the log message in the Console.

Web Platform

• Enabled the WebGPU API (spec; MDN) on Windows. For details, see the Mozilla Graphics Team Blog.

• Implemented the closedby attribute and it's related closedBy property on dialogs indicating the types of user actions that can be used to close the associated <dialog> element.

• Support for Cookies Having Independent Partitioned State (CHIPS) is now re-enabled, allowing developers to opt a cookie into storage partitioning per top-level site.

• The HTMLElement.showPopover() and HTMLElement.togglePopover() methods now take an options.source argument referencing the popover invoker, and togglePopover() also takes a force resp. options.force argument to force the popover open or closed.

Community Contributions

• With the release of Firefox 141, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 12 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:

  • ales.astone: 1920385, 1968910
  • Chris Vander Linden: 1888847
  • Gabriel Astorgano[:astor}: 1911190
  • Jelte Fennema: 1945951
  • Mr. Beedell, Roke Julian Lockhart (RJLB): 1969599
  • Nick Crast: 1965895
  • Sajid Anwar [:sajidanwar]: 825197, 1969770
  • Simon Wülker: 1971080
  • Skye Green [:skyevg]: 1965646
  • viet-hung.nhu: 1968288
  • wilsu: 1956211
  • наб: 1970690

Fixed

• Fixed a startup crash experienced by some Linux users with outdated NVIDIA drivers. (Bug 1978911)

• Fixed a regression that caused canvas objects to be draggable, causing web compatibility issues. (Bug 1978673)

• Fixed a crash in the Web Developer Tools panel that could occur when inspecting pages with <iframe> elements. (Bug 1975277)

• Fixed minor visual issues across the user interface. (Bug 1974269 · Bug 1976031 · Bug 1974876 · Bug 1976701)

• Firefox wouldn't start on some systems where GTK+ was built without Wayland support. (Bug 1978620)

• Fixed an issue where clicking a pinned tab could steal focus from the content area, disrupting keyboard navigation. (Bug 1977005)

• Reference link to 141.0 release notes.

Fixed

• Fixed a regression that caused issues on sites built with the Svelte framework. (Bug 1980081)

• Fixed an issue where cryptominers were not listed as blocked in Strict Tracking Protection. (Bug 1977066)

• Reference link to 141.0.2 release notes.

Fixed

• Fixed a regression that caused issues on sites built with the Svelte framework. (Bug 1980081)

• Fixed an issue where cryptominers were not listed as blocked in Strict Tracking Protection. (Bug 1977066)

• Reference link to 141.0.2 release notes.

Fixed

• Fixed a startup crash experienced by some Linux users with outdated NVIDIA drivers. (Bug 1978911)

• Fixed a regression that caused canvas objects to be draggable, causing web compatibility issues. (Bug 1978673)

• Fixed a crash in the Web Developer Tools panel that could occur when inspecting pages with <iframe> elements. (Bug 1975277)

• Fixed minor visual issues across the user interface. (Bug 1974269 · Bug 1976031 · Bug 1974876 · Bug 1976701)

• Firefox wouldn't start on some systems where GTK+ was built without Wayland support. (Bug 1978620)

• Fixed an issue where clicking a pinned tab could steal focus from the content area, disrupting keyboard navigation. (Bug 1977005)

• Reference link to 141.0 release notes.

New

• Now Firefox can help you keep your tabs organized, automatically. A local AI model identifies similar tabs, automatically organizes them into groups, and even suggests group names. Everything happens on your device to respect your privacy. Learn more here.

  

  

  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.

• Vertical tabs users can now adjust the size of the tools areas at the bottom of the sidebar. To see fewer tools and more tabs, drag down the divider line which pushes extra tools into an overflow menu.

  

• On Linux, Firefox uses less memory and no longer requires a forced restart after an update has been applied by a package manager.

• Address autofill has been enabled for users in Brazil, Spain and Japan.

• The Firefox address bar can now be used as a unit converter. The unit converter supports converting units of length, temperature, mass, force, and angular measurement, as well as timezones (e.g. “now in GMT” , “10am EDT to CET”). Selecting the result will copy it to your clipboard. Learn more here.

  

• Firefox builds in Valencian now come with a built-in Catalan (Valencian variant) dictionary for the Firefox spellchecker.

• The following languages are now available for translation:

  • Albanian
  • Gujarati
  • Hebrew
  • Hindi
  • Kannada
  • Malay
  • Malayalam
  • Persian
  • Telugu

Fixed

• Various security fixes.

Changed

• Firefox on Windows 11 now uses system provided font icons for the caption buttons, more in line with Windows 11 conventions.

Enterprise

• You can find information about policy updates and enterprise specific bug fixes in the Firefox for Enterprise 141 Release Notes.

Developer

• Developer Information

• Firefox will now also clear the back-forward-cache when receiving the Clear-Site-Data: "cache" response header.

• When creating a logpoint in the Debugger, there's now a checkbox allowing to output the stacktrace in addition to the log message in the Console.

Web Platform

• Enabled the WebGPU API (spec; MDN) on Windows. For details, see the Mozilla Graphics Team Blog.

• Implemented the closedby attribute and it's related closedBy property on dialogs indicating the types of user actions that can be used to close the associated <dialog> element.

• Support for Cookies Having Independent Partitioned State (CHIPS) is now re-enabled, allowing developers to opt a cookie into storage partitioning per top-level site.

• The HTMLElement.showPopover() and HTMLElement.togglePopover() methods now take an options.source argument referencing the popover invoker, and togglePopover() also takes a force resp. options.force argument to force the popover open or closed.

Community Contributions

• With the release of Firefox 141, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 12 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:

  • ales.astone: 1920385, 1968910
  • Chris Vander Linden: 1888847
  • Gabriel Astorgano[:astor}: 1911190
  • Jelte Fennema: 1945951
  • Mr. Beedell, Roke Julian Lockhart (RJLB): 1969599
  • Nick Crast: 1965895
  • Sajid Anwar [:sajidanwar]: 825197, 1969770
  • Simon Wülker: 1971080
  • Skye Green [:skyevg]: 1965646
  • viet-hung.nhu: 1968288
  • wilsu: 1956211
  • наб: 1970690

Fixed

• Fixed a startup crash on Windows experienced by some users. (Bug 1974259)

• Reference link to 140.0.1 release notes.

Fixed

• Fixed text contrast issues in the sidebar with some dark themes. (Bug 1971487)

• Fixed a startup crash experienced by some users caused by DLL injection. (Bug 1973947)

• Reference link to 140.0 release notes.

New

• Vertical Tabs: You can now keep more — or fewer — pinned tabs in view for quicker access to important windows. Just drag the divider to resize your pinned tabs section.

  

• Custom Search Engines: Firefox now supports adding even more search engines. To add a custom engine, right-click a search field of a supported website and select “Add Search Engine”, or go to Settings > Search > Add (below the search shortcuts table) to manually enter a search URL.

• Firefox Extensions: Customize your toolbar with the option to remove the extensions shortcut, giving you more control over your browser. When the button is hidden, you can access the extensions panel again at any time from the Firefox menu by clicking the Extensions menu item.

• You can now unload tabs by right-clicking on a tab (or multiple selected tabs) and selecting "Unload Tab". This can speed up performance by reducing Firefox's memory and CPU usage.

• Full-Page Translations now prioritizes translating only the content near your current view, improving speed and responsiveness. Content outside your view is skipped unless you scroll to it, reducing unnecessary resource usage.

• Firefox builds in Arabic now come with a built-in Arabic dictionary for the Firefox spellchecker.

• Address autofill enabled for users in Italy, Poland, and Austria.

Fixed

• Various security fixes.

Changed

• The Pocket toolbar icon, as well as the Pocket integrations on New Tab, have been removed per the service shutdown announcement.

Enterprise

• You can find information about policy updates and enterprise specific bug fixes in the Firefox for Enterprise 140 Release Notes.

Developer

• Developer Information

• Improved the search feature in the Inspector panel to help developers more effectively search the DOM of the current page. Sorting the results by the number of matching elements, support “pseudo” selector state, etc.

Web Platform

• Added platform support for aria-keyshortcuts in Linux, macOS, and Windows.

• Added support for the CookieStore API, an asynchronous cookie API for scripts running in HTML documents and service workers.

• Added support for the Custom Highlight API, which allows styling arbitrary text ranges. Support for text-decoration is not included and is planned for an upcoming release.

• Added support for the pointerrawupdate event. This event provides lower-latency access to pointer movements by firing as soon as the pointer data is available, typically before the main pointermove event. Unlike pointermove, it performs an additional hit test to determine the target and fires more frequently, which may impact performance even if only a listener is added. This event is intended for applications that require high-precision input handling and cannot achieve smooth interaction using coalesced pointermove events alone.

• Service Workers are now available in Private Browsing Mode. This enhancement builds on our efforts to support IndexedDB and the DOM Cache API in Private Browsing through encrypted storage. With this change, more websites, especially those that rely on background tasks, will be able to benefit from Service workers.

• Firefox now applies a uniform user agent (UA) style to <h1> elements, regardless of whether they are used inside <article>, <aside>, <nav>, or <section>.

• Firefox will now escape less-than (<) and greater-than (>) symbols when serializing HTML attributes, making certain mXSS attacks on websites more difficult.

Unresolved

• Users with certain dark themes may experience issues with text contrast in the sidebar. A workaround is to use the built-in dark theme or the system theme
  This is tracked under Bug 1971487 and a fix will follow in a later release. (Fixed in 140.0.1)

Community Contributions

• With the release of Firefox 140, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 18 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:

  • Abhishek Nimalan [:animalan]: 1895919
  • jadavila9: 1852664
  • Jilvin Jacob [:jilvin]: 1902439
  • John McCann [:johnm]: 1952307
  • Jörn Loviscach: 1906974
  • Martin Pitt: 1947402, 1958325
  • Matthias Riffard: 1964530
  • Nathan Mentze:nmentz: 1951703, 1964217, 1965859
  • Patrick: 1955777
  • Peter Collingbourne: 1962497
  • Robert Kirkman: 1946405
  • Rohit Borse: 1953285
  • Sergio: 1930778
  • Tommy: 1579248, 1611813
  • vinhle000: 1950165
  • Xavier Garnier: 1950505
  • Yuto Yoshino: 1911623, 1951699, 1951708, 1960031
  • zhangyilun.0719: 1964665
  • Oleksii Segeda [:Sound]: 1967637

Fixed

• Fixed Firefox freezing when switching between apps or opening certain panels within the browser. (Bug 1969253 & Bug 1969346)

• Fixed difficult selection of drop-down menu options in the Firefox preferences page when selected via the in-page search. (Bug 1968949)

• Fixed various selection issues when triple-clicking text in some situations. (Bug 1969100 & Bug 1969432)

• Fixed an incorrect filename being used when setting an image as the desktop wallpaper on Windows. (Bug 1969793)

• Various security fixes.

• Reference link to 139.0.1 release notes.

Fixed

• Fixed graphics corruption with certain NVIDIA graphics adapters and multiple monitors running at mixed refresh rates after updating to Firefox 139. (Bug 1968876)

• Reference link to 139.0 release notes.