Firefox Updates & Release Notes

Version 154.0, first offered to Release channel users on August 18, 2026

New

Firefox's Local Network Access protections now extend to WebSocket connections. Websites that try to open a WebSocket to a device on the local network will now ask for permission first.

In Smart Window, Firefox can now suggest groups of related tabs and propose a name for each group.

This feature is part of a progressive roll out.

Firefox on Windows is now a supported browser for NVIDIA GeForce NOW, letting users stream supported PC games directly in the browser.

Local Firefox profile backups are now available on macOS in addition to Windows and Linux, and backups can be restored across all three platforms.

Sites can now be exempted from having their cookies and site data cleared on shutdown without also being exempted from tracking protection and other cookie restrictions.

The full-page Translations feature now translates <iframe> content.

The full-page Translations feature now runs language identification on all page loads, resulting in an improved experience for offering translations to users.

Windows users can now choose a different Firefox app icon in Settings. This is not yet available for MSIX installations, macOS, or Linux, but is coming soon.

The address bar now includes a Manage AI quick action that opens the AI controls in Settings.

Performing a hard reload on a page (holding Shift while clicking the Refresh button) now also clears and updates its cached favicons.

Fixed

Fixed an issue on macOS where closing a browser window could leave behind an invisible window that continued to capture mouse clicks over the area where it used to be.

Fixed an issue on Windows where an auto-hiding taskbar would not appear until the Firefox window had been minimized and restored after launch.

Fixed an issue where the Windows taskbar would appear in front of a full screen Picture-in-Picture window.

Fixed the Vertical Tabs sidebar staying visible in full screen mode. It now hides along with the toolbars and reappears when the cursor moves to the edge of the screen.

Fixed PDF documents not being scaled correctly in print preview when the Fit to Page Width option is used.

Various security fixes.

Changed

Video seeking is now significantly faster on all operating systems, making it quicker to jump to a point in a video.

Text selected in a PDF is now highlighted the same way as text on a web page, and the highlight color follows operating system settings such as high-contrast mode.

Firefox View is moving out of the toolbar by default for new profiles and for profiles where it hasn't been used recently. It can still be opened from List all tabs > View all tabs, or added back from the Customize toolbar menu.

Enterprise

You can find information about policy updates and enterprise-specific bug fixes in the Firefox for Enterprise 154 Release Notes.

Developer

The JSON Viewer now shows a breadcrumb path at the bottom for the selected entry.

Web Platform

Firefox now supports the text-box-trim and text-box-edge CSS properties, and the associated text-box shorthand. These properties control the leading space above and below text, enabling simpler and more consistent vertical spacing and alignment.

Firefox now supports the sibling-index() and sibling-count() CSS functions. These functions allow an element to be styled with calculations that use its index among its siblings and its total count of siblings (including itself), respectively.

Added a time picker user interface to <input type="time"> and <input type="datetime-local">, making selecting a time more accessible and intuitive.

Added support for the No-Vary-Search HTTP response header for the HTTP disk cache. Servers can now declare which URL query parameters are irrelevant to the response, allowing Firefox to reuse cached resources across parameter variations and improving cache hit rates.

Firefox now supports new Iterator.prototype.chunks and Iterator.prototype.windows methods that allow consuming an iterator as either overlapping or non-overlapping subsequences of configurable size.

Firefox now supports Iterator.prototype.includes(), allowing developers to check whether an iterator contains a given value without first converting it to an array.

Firefox now supports the Iterator.prototype.join method, which allows joining an iterator into a string, similar to Array.prototype.join.

Community Contributions

With the release of Firefox 154, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 32 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:

Ale Camara [:ale]: 2054573
andra: 2022992, 2046118
andrea.distefano: 1470011
Anil Verman: 2040057
Benoit: 2047559, 2049316, 2050403
Brieuc Gommard: 2031346, 2049309
christopher.staite: 2037813
conor: 1988166
Cornelius | CE student: 2046119
Devin Rousso: 2052932
Diego: 2018728
elvyria: 2027522
Gabe: 2049141
Hagen: 2049264
Hillwood Yang: 2048250
Jaimukund Bhan: 2034642
Kafji: 2051493
Kometes: 1954212
Luiz Henrique Vieira: 2050546
Majed El-Barbari: 2040240
Marcelo Camargo: 2009295
Mayank Bansal: 2055744
muhammad shaikh: 2016932
Raimund Hook: 2050794
Rebekah: 2052857
Riza: 2044167
Ronak Sheth: 2048099
taylor: 1419649
Tim McNulty: 2052560
Yogeshdangal66: 2031348
Zehui Xu: 2028402
占旭哲: 1992363

Version 153.0.3, first offered to Release channel users on August 4, 2026

New

Smart Window includes several enhancements:

• The suggestion list now shows more results, making it easier to find history and switch to open tabs. (Bug 2019042)
• The assistant can now answer questions directly using web search results from Exa, instead of handing off to a search engine. (Bug 2046183, Bug 2044385)

This feature is part of a progressive roll out.

Fixed

Fixed audio and video failing to play, or hanging when seeking, on websites that load media from a Blob URL. (Bug 2056444)

Fixed Internet shortcuts dragged from Firefox to the desktop being marked as untrusted on Windows, which caused a security warning every time they were opened. (Bug 2056865)

Fixed the Bookmarks, History, and other sidebars failing to open when the sidebar is hidden and the password manager has been turned off by an enterprise policy. (Bug 2056857)

Fixed a Mozilla VPN upgrade offer appearing for people in regions where Mozilla VPN is not sold. (Bug 2058264)

Fixed frequent Inspector crashes in the Developer Tools on pages where an extension content script had added event listeners. (Bug 2042101)

Fixed a rare case on Windows where starting Firefox while a partial update was still being applied could leave the installation broken and unable to start. (Bug 2058197, Bug 2058594)

Reference link to 153.0.1 release notes.

Version 153.0.1, first offered to Release channel users on July 28, 2026

Fixed

• Addressed a startup crash on Windows that could occur after updating Firefox, when some of the application's internal files could not be loaded. Firefox should now start in these cases, although parts of the interface may not display correctly until a further update completes (Bug 2056926).
• Fixed audio playing silently on some music and audio streaming sites after pausing and resuming playback (Bug 2053586).
• Fixed the New Tab page background flashing a few seconds after the page loaded when a custom wallpaper was in use (Bug 2056650).
• Fixed a crash that could occur when a page loaded a frame using a javascript: address (Bug 2054485).
• Fixed a crash that could occur while typing text in an editable area of a page (Bug 2053867).
• Fixed a search engine you had already installed yourself being labeled as "New" when Firefox later started offering the same engine (Bug 2053710).
• Improved pointer lock, used by games and other immersive web content, so that the mouse pointer is less likely to escape the Firefox window (Bug 1255338, Bug 2040628).
• Fixed an issue in the Inspector's Rules view where pseudo-elements could only be expanded once per selected element (Bug 2054525).
• Fixed View Page Source failing to load blob: documents (Bug 2054428).
• Fixed View Page Source timing out on documents that inherit their origin, such as frames using the srcdoc attribute (Bug 2054487).

Reference link to 153.0 release notes.

Unresolved

• Some Windows users may experience a crash on startup after updating, caused by an incomplete update leaving the Firefox installation in an inconsistent state (Bug 1681745). If you are affected, downloading Firefox from firefox.com and installing it over your existing installation will repair it. Your bookmarks, passwords and other data are stored separately and will not be affected.

Version 153.0, first offered to Release channel users on July 21, 2026

New

High Dynamic Range (HDR) video playback is now available on Windows - this feature needs HDR mode enabled for the display in Windows Settings - Display. Laptop displays that only offer "HDR video streaming" are not supported at this time. Some videos recorded on phones in certain orientations are currently not shown as HDR.

Containers let you keep separate parts of your online life (work, shopping, personal, banking) logged into different accounts in the same browser window, but keep your cookies and ad tracking isolated inside each container.

Share any open page with a QR code. Right-click a tab, select Share > Generate QR Code. Great for posters, invitations, banners, and other printed materials.

It is now possible to merge multiple PDFs by dragging a PDF into the PDF sidebar.

It is now possible to add images as new pages within PDFs using the Firefox PDF editor.

Quickly pick and copy a color from any page by typing "pick color", "color picker", or "eyedropper" in the address bar and selecting the "Pick a color" quick action.

Added support for Apple's system-wide full-screen keyboard command (Globe-F).

Firefox now verifies and displays Qualified Website Authentication Certificates (QWACs) in accordance with eIDAS regulations.

Added improved support for videos with overlays so users can more easily access video actions from context menus.

Firefox now highlights the location permission icon in red whenever a website has access to your location. The permission icon is also now visible on search results pages where it was previously hidden.

Smart Window:

• See and choose AI models directly from the Smart Window assistant.
• New Tab now includes a familiar address bar for typing websites and searching the web.

This feature is part of a progressive roll out.

Firefox Labs

Firefox Labs can now be opened quickly by typing "labs" or "experiment" in the address bar and selecting the Open Firefox Labs quick action.

Firefox now offers experimental support for the new JPEG XL image format, which generally provides better compression than WebP, JPEG, PNG, and GIF and is designed to supersede them. You can enable it from the Firefox Labs panel in Settings.

Fixed

Various security fixes.

Changed

Extensions can no longer access local files by default. Users can grant or revoke this access via the new "Access local files on your computer" permission, separate from "Access your data for all websites".

Local Network Access restrictions are now enabled by default for all users. Firefox requires websites to request permission before connecting to devices on your local network or to apps and services on your device.

Outdated cookie settings have been removed from the Settings UI. Users still in that mode should switch to default behavior "Isolate cross-site cookies". More information

Enterprise

You can find information about policy updates and enterprise-specific bug fixes in the Firefox for Enterprise 153 Release Notes.

Developer

Developer Information

A new "Local Mode" setting in the options panel allows developers to load local directories via custom origins. This simplifies testing for APIs that do not function over standard file:// URLs, removing the need to run a local web server. Multiple directory mappings are supported.

Web Platform

Firefox now supports a limited subset of the non-standard ::-webkit-scrollbar pseudo-element to improve web compatibility:

• Rules with non-zero width / height disable overlay scrollbars for the affected container.
• display: none on ::-webkit-scrollbar behaves like scrollbar-width: none, hiding the scrollbar.
• @supports selector(::-webkit-scrollbar) now evaluates to true.
• Full styling capabilities (colors, border-radius, etc.) are intentionally not supported.

The vertical-align property was converted into a shorthand for baseline-source, alignment-baseline, and baseline-shift in Firefox 149. Now, alignment-baseline supports the new keywords alphabetic, ideographic, central, mathematical, and hanging, extending the variety of baselines to choose for alignment.

Implemented the new popover=hint spec, which removes a series of inconsistent and unexpected behaviors.

The circle() and ellipse() functions accept two new keywords closest-corner and farthest-corner for their radial size.

The newly added Error.stackTraceLimit property allows to set the maximal depth of the captured JavaScript error stack as a performance optimization.

Developers can now use the text import attribute to import text files using the module system.

The Picture In Picture API exposes a way for web developers to make use of user agent Picture-In-Picture functionality.

The Intl.LocaleInfo proposal adds the ability to query Locale information, such as week data (first day in a week, weekend start day, weekend end day), text direction and hour cycle used in the Locale.

The MediaCapabilities.decodingInfo() and MediaCapabilities.encodingInfo() methods now accept the "webrtc" configuration type. This allows a site to query whether a given audio or video configuration can be decoded or encoded for WebRTC and whether doing so will be smooth and/or powerEfficient.

HTTP Compression Dictionaries is enabled via rollout in 153, it will be made permanent in a future release. This can greatly reduce network traffic size for sites that use it.

This feature is part of a progressive roll out.

Community Contributions

With the release of Firefox 153, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 15 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:

• Alan Liu: 2009570
• Dineth De SIlva: 2042443
• Freya Arbjerg [:freyacodes]: 2036767
• Garbee: 2045887
• Jessica Foley: 2041062
• John ARNZEN: 2046279
• Max Emig [:maxe]: 230112
• metamuffin: 2045549
• mtan: 2039500
• ozcoder: 2020186
• Pedram Yektamaram: 2042437, 2042440, 2042441, 2042442
• Peter Lafreniere [:n8pjl]: 2041463
• Phone Khant Kyaw Swa: 2008877
• pullmana8: 2031735
• Ryan McCartney: 2039853

Version 152.0.6, first offered to Release channel users on July 14, 2026

New

Smart Window includes several enhancements:

• Select text on a page and get quick access to summarize, explain, and more using the built-in assistant. (Bug 2034921)
• Added a row of shortcuts to New Tab, making it easier to get back to sites. (Bug 2048338)

This feature is part of a progressive roll out.

Fixed

Fixed an issue that prevented email tracking protection from being disabled in the redesigned Firefox Settings. (Bug 2049331)
Fixed a hang that could occur after using a file picker dialog on macOS 26. (Bug 2053177)
Fixed the homepage not loading for some enterprise configurations that set it using a legacy autoconfig format. (Bug 2047962)
Various security fixes.

Reference link to 152.0.5 release notes.

Version 152.0.4, first offered to Release channel users on June 30, 2026

New

Smart Window includes several enhancements:

• You can now ask it to close your tabs, with a confirmation step when needed and the option to undo afterward. (Bug 2040769)
• Browsing history results now appear with images. (Bug 2038069)
• When you give feedback on a response, you can now choose from common reasons and preview exactly what will be shared before submitting. (Bug 2033002)

This feature is part of a progressive roll out.

Fixed

Fixed copy, paste, undo, redo, and similar keyboard shortcuts not working inside macOS system dialogs such as the Save and Open panels. (Bug 2040851, Bug 2040844)
Fixed the Manage Cookies and Site Data dialog opening with an empty list when opened from the Settings search results. (Bug 2041077)
Fixed keyboard focus landing in the wrong place after following an in-page link, so pressing Tab continues from the link's position as expected. (Bug 2049307)
Various security fixes.

Reference link to 152.0.3 release notes.

Version 152.0.2, first offered to Release channel users on June 23, 2026

Fixed

Fixed some Settings section headings showing placeholder text instead of the translated name in certain languages. (Bug 2047983)

Fixed New Tab content not matching the browser's display language after it was changed. (Bug 2046945)

Fixed a regression that could break playback of some MP4 video files. (Bug 2047467)

Fixed a performance regression that could slow down sites performing many encryption and decryption operations at once, such as Proton Drive. (Bug 2046401)

Reference link to 152.0.1 release notes.

Unresolved

Some users with a language pack installed may experience high memory usage and an unresponsive browser on startup. (Bug 2049845)

Version 152.0, first offered to Release channel users on June 16, 2026

New

• Firefox Settings features a brand-new look with streamlined organization, clearer groupings, and improved navigation for easier customization.
• In Private Browsing windows, you can now temporarily disable tracker blocking for a tab if it's causing a site to break. When you reload a page where trackers were blocked, Firefox shows a message offering to reload without the stricter protections. All other tracking protections stay active.
• You can now mute your browser from the address bar: type "mute" (or "shush" or "sssh") and use the address bar quick action to silence every tab currently playing sound across all Firefox windows.
• Improved support for more advanced cursor movement commands, including those relating to paragraph boundaries, on macOS.
• On Windows and Linux, you can now copy links via the tab context menu by right-clicking a tab and selecting Share > Copy Link, making it easy to copy a link without switching to the tab first. When multiple tabs are selected, you can copy all selected links at once. Windows users still retain access to Microsoft sharing options from the Share menu.
• A "Send tab" toolbar button is now available which can be added via More Tools > Customize Toolbar.
• The following languages are now available for Translations: Basque, Galician.
• Firefox builds in Croatian, English (UK), Georgian, Persian, Slovenian, Tajik, Tamil, Tibetan, Turkish, Welsh, and Xhosa now come with a built-in dictionary for the Firefox spellchecker.

Firefox Labs

• Firefox now offers experimental support for the new JPEG XL image format, which generally provides better compression than WebP, JPEG, PNG, and GIF and is designed to supersede them. You can enable it from the Firefox Labs panel in Settings.

Fixed

• Fixed an issue where the Paste option could be missing from context menus when editing content on sites such as Squarespace, LinkedIn, and eBay.
• Improved dragging images from Firefox to the desktop or Finder on macOS — images now save reliably and land where you drop them.
• In multiple monitor situations, the About Firefox window now more reliably opens on the display with the most recently used Firefox window.
• Fixed arrow-key text navigation and word selection commands that moved in the wrong direction in right-to-left text on macOS and Linux.
• Various security fixes.

Changed

• Site zooming via keyboard or mouse now offers more zoom levels in smaller increments than before.
• When a PDF or other file that Firefox opens directly finishes downloading, it now opens in a background tab if you've switched tabs or closed the original page.
• The Tabs from Other Devices panel in the sidebar now lets you open tabs in a new tab or a new container tab from the context menu.

Developer

• Developer Tools now have an option in the Settings panel to toggle the display of comment nodes in the Inspector.

Web Platform

• Web Notifications can now have action buttons via the actions option. They appear as buttons below the notification text or in the Options list on macOS.
• The field-sizing property is now available, allowing form controls to adjust in size to fit their contents.
• Firefox now supports the WebAuthn Related Origin Request feature, which simplifies login flows by making Passkeys usable from multiple domains.
• The Pointer Lock API now supports the unadjustedMovement option, allowing sites to receive raw mouse-movement data unaffected by OS-level acceleration.

Community Contributions

With the release of Firefox 152, 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: :23rd: 1812100, :Vincent: 2033780, Akeem Omosanya: 2031351, 2035252, Amin Amir: 2031353, 2031355, 2031599, 2033820, Amine Zroual: 1392125, Andrew Gaul: 2032275, Andy [:rgbcmy]: 1611643, Eugeniusz Lewandowski: 1650944, 2036580, Helmut Januschka: 2006340, Jak: 2030070, JIANG Zhirui: 2036199, liz: 1875083, 2008119, 2011485, Mubashshir: 1803078, Noah Peterson: 1829401, Rahman Mahmutović [:r_m]: 1717176, Sahaj: 2031015, Takeru Mitsumori: 2038948, Tim Elliott: 2031507, tom.passarelli: 2031328, Tymur Boiko: 2035749, 2036839, 2039309, Vignesh B [:vsr-b]: 1895393, 1966844, vinitjangir: 790194, 2000360, vyofgod: 2031349, 2031356, 2031357, 2031371, 2031377, 2031381.

Version 151.0.4, first offered to Release channel users on June 9, 2026

Fixed

Fixed an issue on Windows where Firefox could become unresponsive when using the back and forward buttons. (Bug 2039866)

Fixed an issue where Firefox could fall back to software rendering on some older GPUs, reducing graphics performance. (Bug 2043249)

Fixed a crash on Windows that could occur when Firefox interacted with accessibility services. (Bug 204330)

Fixed an issue where some text input fields could incorrectly show a resize handle. (Bug 2044051)

Reference link to 151.0.3 release notes.

Version 151.0.2, first offered to Release channel users on May 26, 2026

Fixed

Fixed an issue on macOS where smart cards and security keys could fail to load certificates automatically. (Bug 2041208)
Fixed an issue where adding another tab to an existing Split View could unexpectedly close it. (Bug 2039795)
Fixed an issue where Split View would close instead of switching tabs when using the "Switch to Tab" option from the address bar. (Bug 2039787)
Fixed a crash on Windows that occurred when using the Sogou input method to type Simplified Chinese. (Bug 2039203)
Fixed an issue where Firefox stopped caching new content once the disk cache was full, causing pages and resources to be re-downloaded from the network on every visit. (Bug 2031577)
Fixed an issue where some websites could render incorrectly or fail to load when they used JavaScript to insert WebKit-specific style rules. (Bug 2040693)
Fixed an issue where clicking and selecting text in some input fields and text areas did not work on pages that styled them with certain CSS rules. (Bug 2039504)
Fixed an issue where the up and down buttons on number input fields could overlap and hide the value when sites sized the field to fit its contents. (Bug 2039315)
Fixed an issue where sorting strings that include numbers could produce an incorrect order on some websites and web applications. (Bug 2027078)
Fixed an issue where dropdown menus would not open for <select> elements created inside an iframe and then moved into the parent page. (Bug 2041720)

Reference link to 151.0.1 release notes.