Firefox Updates & Release Notes

Version 157.0, first offered to Release channel users on September 29, 2026

New

Firefox's biggest visual refresh in years is now available, with a modernized look across the browser toolbars, sidebar, menus and individual features, built with our updated design system. It also includes:

• New built-in themes with light and dark versions, to personalize the look of Firefox in one click.
• A new compact mode that reduces toolbar and tab spacing to leave more room for web content, useful on smaller screens and in split-screen layouts.

WebRTC video calls can now use hardware AV1 decoding on devices that support it, instead of always decoding AV1 video in software.

Firefox now shows a warning in the site information panel (the shield icon in the address bar) and in Settings when it has been set up to record its encryption keys, which could let other software on the computer read encrypted web traffic.

Firefox Suggest now offers suggestions in the address bar in Austria, Belgium, Czech Republic, Denmark, Finland, Hungary, Ireland, Luxembourg, Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, and Switzerland. They can be controlled in the Firefox Suggest settings. Learn more.

Fixed

Fixed video from phones and tablets appearing sideways or upside down in WebRTC calls.

Fixed the address bar searching for the typed text instead of opening the selected suggestion when a page was still loading, such as shortly after Firefox started.

Fixed some HDR videos encoded in 8-bit color formats looking dull and gray on Windows instead of displaying in HDR.

Improved audio and video synchronization when repeatedly changing the playback speed of videos, for example on YouTube.

Fixed the Vertical Tabs sidebar not reappearing when the cursor moves to the edge of the screen in full screen mode.

Fixed an issue on Windows where making a video full screen would leave the Windows taskbar showing over the video.

Various security fixes.

Changed

Pressing Tab now moves focus straight to the text field of the address bar and search bar instead of stopping on the search engine button first. The button can still be reached with Shift+Tab.

Amazon is no longer included as a built-in search engine. It can still be added as a custom search engine in the search settings. Learn more.

The updated sidebar is now enabled for everyone. Anyone still using the previous sidebar will keep a similar layout, with the panel switcher at the top of the sidebar. Additionally, the “Show sidebar” option has been removed from Settings.

While we continue to refine the new design, the previous sidebar version can still be restored by setting sidebar.revamp to false in about:config. This also turns off vertical tabs. The preference will remain available until the end of 2027.

Web page alert(), confirm(), and prompt() dialogs, the color and date pickers, and form autocomplete drop-downs now match the page's light or dark color scheme.

Enterprise

You can find information about policy updates and enterprise-specific bug fixes in the Firefox for Enterprise 157 Release Notes.

Developer

Developer Information

Web Platform

Firefox now supports the at-rule() function for @supports. This allows authors to detect browser support for specific at-rules, such as @supports at-rule(@scope).

Firefox now supports the chain value for the CSS overscroll-behavior property.

Community Contributions

With the release of Firefox 157, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 21 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:

• Alexander Gankov: 2033184
• Amadi: 2053549, 2053553, 2065302, 2066478
• Andrew: 2031465
• Caleb Pickard: 2058970
• David Torcivia: 2057758
• dchen705: 2065655
• Ekerin Agboola: 2064541
• Giddeon Card: 2067328
• gustavokrm: 2051536
• Hanzala Sohrab: 2068111
• Ivan Smagin: 2061540
• Jieke Jiang: 2067179
• Nazeer Ahmed Shaikh: 1703780, 2064544
• Noah Varghese: 1625924, 2021799
• perdomojuan755: 2069230
• Raúl: 2066877
• Rév O'Conner: 1594489
• Samuel Mbabhazi: 2054228
• sfshah: 2004273, 2067302
• Valerie Racine (:v-racine): 1849963
• Xiaosen Zhuang: 2069280

Version 156.0.1, first offered to Release channel users on September 22, 2026

Fixed

• Fixed the NVDA screen reader not announcing address bar buttons when the mouse pointer moves over them. (Bug 2069276)
• Fixed elements inside a link not showing their CSS :active styles while being clicked. (Bug 2067272)
• Fixed Firefox becoming unresponsive on some pages that use CSS anchor positioning. (Bug 2070171)
• Fixed Firefox windows on macOS 27 immediately returning to maximized after being restored by double-clicking the title bar. (Bug 2066632)
• Fixed Firefox leaking system handles on Windows as content processes were started and stopped. (Bug 2069644)

Changed

• Pressing Tab now moves focus straight to the text field of the address bar and search bar instead of stopping on the search engine button first. The button can still be reached with Shift+Tab.

Reference link to 156.0 release notes.

New

• Firefox on macOS can now be set to open automatically when the computer starts up, from the Startup section of Settings.
• Localized Wikipedia and occasional sponsored suggestions in the address bar are now available in France, Germany, and Italy. These suggestions can be turned off in Firefox Suggest settings.

Fixed

• Fixed an issue where dragging an image to a new position in a rich-text editor could replace it with a long line of text instead of moving it.
• Fixed high-sample-rate FLAC audio in MP4 failing to play on sites such as Bilibili.
• Fixed subtitles not appearing in the Picture-in-Picture window when they are turned on in the video player after the window has already opened.
• Fixed bookmarks moving out of their folder when the folder and the bookmarks inside it were selected and dragged together in the Bookmarks sidebar.
• Fixed the find bar becoming permanently unavailable in a tab after reversing the panes in Split View.
• Fixed some sites failing to load when DNS over HTTPS is enabled and the site does not support HTTPS.
• Fixed Firefox losing all network connectivity for some users with the built-in VPN enabled.
• Fixed an issue on Windows where Firefox could block an auto-hiding taskbar from showing.
• Various security fixes.

Changed

• Firefox's built-in PDF viewer now starts up to 45% faster.
• Improved memory and CPU usage when Firefox displays large JPEG images scaled down to fit a page.
• On Windows devices with ARM64 processors, WebRTC video calls may now use hardware H264 decoding instead of falling back to software.

Enterprise

• You can find information about policy updates and enterprise-specific bug fixes in the Firefox for Enterprise 156 Release Notes.

Developer

• Developer Information

Web Platform

• text-box-trim now uses the font metrics of a ::first-line pseudo-element when one applies, matching other browsers and the specification.

Community Contributions

With the release of Firefox 156, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 10 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:

• Aaron Ma: 2063818
• Dominik Bay [:eimann]: 2066736
• ExplodingJoysticks: 1728637, 1890400, 1910664, 1928343, 1944206, 2000658, 2003000, 2059911, 2061541
• Gopalarathnam Venkatesan: 2003172, 2042426, 2062096, 2062952, 2062989
• Hugo Osvaldo Barrera: 2063808
• Kana: 2062133
• Kerissa Grubb: 2042422
• Louis-Philippe Manette: 2062972, 2063867
• Seunghyun An: 2063033
• William McDonald: 1034964

Version 155.0.1, first offered to Release channel users on September 4, 2026

Fixed

• Fixed Firefox becoming unresponsive on some pages that use CSS blur and backdrop filters together. (Bug 2068836)
• Fixed the sidebar not reappearing after restarting Firefox when the "Hide tabs and sidebar" option was turned on. (Bug 2065431)
• Fixed some profile icons not being displayed in the account and application menus. (Bug 2064729, Bug 2067734)
• Fixed the current device being listed among connected devices in the account menu. (Bug 2059763)

Reference link to 155.0 release notes.

Unresolved

Standard dynamic range (SDR) video in some formats can appear washed out on macOS. The issue is under investigation and a fix will ship in a future release. (Bug 2068961)

New

Smart Window is now available for all users in the USA, Canada, and France to try out! Additionally, Firefox 155 includes many new enhancements:

• New personalized resume conversation starters help users quickly return to topics they’ve been working on.
• Assistant now responds much faster with Exa web search source citations to provide accurate, trustworthy web grounding in roughly 1/5 the time.
• Organize Tabs now suggests better groupings of your related tabs and gives each group a clearer, more descriptive name.

This feature is part of a progressive roll out.

Firefox now shows how many trackers it has blocked in the address bar, making built-in privacy protections easier to see while browsing. The count can be hidden in settings without turning off tracker blocking.

This feature is part of a progressive roll out.

Nintendo Switch Pro and compatible aftermarket controllers now work fully in web games on Windows, with the directional pad and analog sticks correctly mapped.

Containers can now be reordered in Settings, and the new order is used wherever containers are listed.

The Translations feature now supports the following languages:

• Marathi
• Urdu

Fixed

Fixed text disappearing in Microsoft 365 Word Online and other web apps on Linux when typing with certain keyboard layouts.
Fixed an unnecessary paste confirmation appearing when using the keyboard shortcut to paste without formatting in Google Docs.
Firefox now recovers from the toolbar and tab strip being left unresponsive when the platform fails to end a tab drag session.
Fixed text inside buttons not being selectable or copyable, which prevented copying direct messages on X and comments on YouTube.
Fixed live audio streams such as internet radio stopping when playing in the background.
Fixed the sound indicator disappearing from a tab that was moved to another window, leaving no way to see or mute what was playing.
Fixed Firefox preventing Linux systems from going to sleep after a long browsing session.
Fixed full screen content being letterboxed on MacBooks with a camera notch, most visibly when watching video.
Fixed arrow-key and Page Up/Down scrolling not working on some pages with embedded content from other sites.
Fixed characters from some less common scripts appearing as empty boxes on web pages on Windows.
Fixed WebCodecs VideoEncoder hanging on macOS when encoding a VideoFrame in NV12 format.
Various security fixes.

Changed

Firefox now limits CSS to 75 levels of nested blocks and functions, preventing crashes that extremely deep nesting can cause under some circumstances. More deeply nested rules and values no longer parse.
Firefox now uses firefox-portal-detection.com instead of detectportal.firefox.com to detect captive portals and check network connectivity, so network allowlists referencing the old domain need updating.
Firefox now opens mailto: links only in response to an explicit user action, so pages can no longer launch the default mail client unprompted.
PDFs smaller than the paper size can now be enlarged to fill the sheet when printing, by setting the scale above 100%.

Enterprise

You can find information about policy updates and enterprise-specific bug fixes in the Firefox for Enterprise 155 Release Notes.

Developer

Developer Information

The Rules View now offers toggles to emulate the prefers-reduced-motion media feature. Emulation options have also moved into a new panel behind the at-rules (@) button.
The Debugger in Developer Tools now has a keyboard shortcut, Ctrl+Alt+B (Cmd+Alt+B on macOS), to enable or disable all breakpoints at once.
The JSON Viewer now displays JSON Lines (JSONL/NDJSON) documents, including inline errors for invalid lines.
Fixed the Storage panel showing cookies from private windows, containers, and other partitions alongside the inspected page's own cookies.
Uncaught non-Error exceptions now list their property names in the Console instead of showing only Object.

Web Platform

The CSS attr() function now supports values of any type, so authors can use attribute values in any property rather than only as strings in the content property.
Firefox now supports the progress() CSS function.
Firefox now supports the alpha() CSS function. This is a relative color function that can be used to modify just the alpha component of a given color.
Firefox now supports the Promise.allKeyed and Promise.allSettledKeyed methods from the await dictionary proposal, which take an object of promises and resolve to an object of results with the same keys.
Firefox now supports the WebAssembly Compact Import Section proposal, which can reduce the size of WebAssembly modules with many imports.
Firefox now supports the WebAssembly Wide Arithmetic proposal, which adds 128-bit arithmetic instructions for better performance in cryptography and arbitrary-precision math.
Firefox now supports QUIC version 2 (RFC 9369) for HTTP/3 connections, and uses it when the server selects it through compatible version negotiation (RFC 9368).
Support for the non-standard ::-webkit-scrollbar pseudo-element, added in Firefox 153, is now limited to a small list of sites rather than applying universally.
SVG elements now expose the same URL properties as HTML links, including protocol, host, pathname, and search.
SVGGraphicsElement.getBBox() now honors its options argument, so bounding boxes can include stroke, markers, and clipping.
The font-width property is now supported as the standard name for font-stretch.
A dynamic import() that fails due to a network or HTTP error is no longer cached as a failure in the module map, so retrying the same specifier can now succeed.
WebTransport now supports send groups (createSendGroup()) for controlling how bandwidth is shared between streams, writable datagram streams (createWritable()), and exportKeyingMaterial() for deriving keys bound to the TLS session. It also adds a draining promise and subprotocol negotiation through the constructor's protocols option and the protocol property.
Firefox now supports RTCError for data channel failures, RTCSctpTransport.maxChannels, two-byte RTP header extension IDs, and more accurate RTCTransportStats, improving WebRTC interoperability.

Unresolved

For users with vertical tabs enabled, the sidebar may not persist across Firefox restarts. Vertical tabs can be re-enabled after the restart by clicking the sidebar toolbar button. A fix is currently in development. (Bug 2065431)
Some sites may load slowly or fail to load on networks that block UDP. This can affect e.g. corporate networks where a proxy or firewall blocks QUIC as part of TLS inspection. To work around it, set network.http.happy_eyeballs_enabled to false with the Preferences policy. A fix is planned for the 155.0.1 release shipping no later than 8-September. (Bug 2063452)

Community Contributions

With the release of Firefox 155, 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:

• Artem Bilous: 2056733
• Cameron: 2052559, 2052619
• Colden Cullen: 2060708
• Dan: 1735300
• Fede: 1418178, 2040498, 2046774
• Giulio B: 2048884
• K: 1642578
• Kevin Gosse: 2054036
• Michael F: 2052438
• mikey gough: 2053551
• munawiki: 2055309
• Nathan Leuz: 2053550
• Nirmal Advani: 1804108, 2003174, 2003177, 2003181, 2031618, 2033570, 2046156, 2052618, 2053543, 2053566, 2053568, 2053977, 2058556, 2059866, 2060649
• Priyanshu[:0xanshu]: 1977947
• Richard Van Natta[:rnvannatta]: 2052617
• Ruhollah Majdoddin: 1856645, 2060029, 2061166, 2061348
• Shawn Zivontsis: 2025999
• Simon Rosen: 1875517
• Yuxiao Zhu: 1861034
• Zyphrenn: 2033961, 2059969

Version 154.0.1, first offered to Release channel users on August 25, 2026

Fixed

Fixed slower access to saved passwords and unexpected Primary Password prompts caused by recent changes to password storage. (Bug 2064411, Bug 2065593, Bug 2063993)

Fixed an issue where addresses were failing to autofill on some sites. (Bug 2065145, Bug 2063599)

Fixed Firefox adding a new Start Menu shortcut on Windows every time it started. (Bug 2064652)

Fixed an issue where connections to local network devices were failing without a permission prompt on some sites loaded over HTTP. (Bug 2059274)

Fixed a crash that could occur when opening intranet sites that are configured to link to files on a local network share. (Bug 2064648)

Fixed an issue on Windows where tab titles were cut off at the start when the system font was MS UI Gothic. (Bug 2056856)

Reference link to 154.0 release notes.

Unresolved

For users with vertical tabs enabled, the sidebar may not persist across Firefox restarts. Vertical tabs can be re-enabled after the restart by clicking the sidebar toolbar button. We are currently working on a fix. (Bug 2065431)

When toolbars are hidden in fullscreen mode (the default on Windows and Linux), the vertical tabs sidebar does not appear when moving the cursor to the left edge of the screen. As a workaround, move the cursor to the top of the screen to reveal both toolbars and sidebar together. Alternatively, you can also right-click the toolbar and uncheck the Hide toolbars option. We are currently working on a fix. (Bug 2064638)

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.

Unresolved

Following recent changes to Firefox’s Address Autofill logic, some users may experience autofill failures when auto-filling addresses.
We’ve rolled out a fix, and we’re closely monitoring the results. (Bug 2065145)

Following recent changes to Firefox’s password storage, some users may experience slower performance when Firefox accesses saved passwords. Users with a Primary Password enabled may also see unexpected password prompts, such as when starting Firefox or opening certain content.
We’ve rolled out a mitigation for this issue and are continuing to work on further improvements to the experience. (Bug 2064411)

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.