Firefox 159.0
New
Sharing on macOS now uses the native macOS share picker, which shows a preview of the page and recent contacts alongside AirDrop, Messages, and other apps. Several selected tabs can also be shared at once.

Saved passwords are now available from the sidebar by default, without having to add the Passwords tool first.

Smart Window can now watch pages for changes such as price drops or restocks. Type
/watchin the chat to set one up, and Firefox sends a desktop notification when it finds a match. Watches can be managed from the Tasks button in the toolbar or theabout:smartwindowtaskspage.
Fixed
Fixed the file upload dialog opening in the last folder a file was saved to, such as Downloads, instead of the folder last used for uploads.
Fixed memory usage growing rapidly when sites such as the Zoom web app were left open in a minimized window.
Fixed some videos displaying incorrectly on Windows when NVIDIA RTX Video HDR is enabled.
Fixed bookmarks not being imported from Google Chrome profiles that are signed in to a Google account.
Fixed the Replace button in Apple Writing Tools on macOS inserting the clipboard contents instead of the rewritten text on some sites, such as Gmail.
Fixed long drop-down lists on web pages sometimes showing blank space in place of the last options until the list was scrolled.
Fixed some sites, such as Slack, failing to load instead of falling back to HTTP/2 when the site rejected an HTTP/3 request.
Fixed Firefox using excessive memory on Linux with AMD graphics when viewing map or place results on sites such as ChatGPT.
Fixed quick gamepad button presses sometimes being missed in web games on macOS.
Fixed tabs sometimes detaching into a new window when clicked on Linux with Wayland.
Fixed menus and panels fading in on Windows and Linux when animation effects are turned off in the operating system.
Various security fixes.
Changed
On macOS, apps that sign in through the default browser, such as ChatGPT, now open their sign-in page in Firefox instead of Safari when Firefox is the default browser.
The AI chatbot's Summarize page option now sends the page's address to the chatbot provider instead of the page's text, so long pages are no longer cut short to a partial summary.
Open tabs can now be searched with a keyboard shortcut:
Ctrl+Shift+Aon Windows and Linux,Cmd+Shift+Aon macOS. The Extensions and Themes shortcut is nowCtrl+Shift+Fon Windows and Linux, andCmd+Shift+Eon macOS. These shortcuts can be changed inabout:keyboard.Web addresses written in the Javanese, Balinese, Canadian Aboriginal Syllabics, and N'Ko scripts are now displayed in their own script instead of as encoded "xn--" text.
Enterprise
For Firefox Enterprise updates and fixes, see the Firefox Enterprise release notes. For policy changes, see the Firefox admin docs changelog.
Developer
- Developer Information
The Web Console now allows
let,const, andclassvariables to be declared again, so a snippet can be edited and re-run without a redeclaration error.
Web Platform
Firefox now supports scroll-driven animations, so CSS animations and Web Animations API animations can progress with the scroll position of a container or with an element's visibility as it scrolls into view. This adds the
animation-timeline,scroll-timeline,view-timeline, andanimation-rangeproperties and theScrollTimelineandViewTimelineinterfaces.Firefox now supports scoped custom element registries. A registry created with the
CustomElementRegistry()constructor is separate from the globalwindow.customElementsregistry, so custom elements that share a tag name can coexist on the same page.On compatible devices, WebGL now supports the
EXT_clip_controlandEXT_texture_mirror_clamp_to_edgeextensions and WebGL 2 supportsEXT_texture_norm16.The Sanitizer API now sanitizes HTML as it is parsed rather than afterwards, so custom element constructors no longer run for elements the sanitizer removes.
Community Contributions
With the release of Firefox 159, 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: