Download Firefox

Firefox is no longer supported on Windows 8.1 and below.

Please download Firefox ESR (Extended Support Release) to use Firefox.

Firefox is no longer supported on macOS 10.14 and below.

Please download Firefox ESR (Extended Support Release) to use Firefox.

Firefox Privacy Notice

Firefox Beta and Developer Edition
Release Notes

Release Notes tell you what’s new in Firefox. As always, we welcome your feedback. You can also file a bug in Bugzilla or see the system requirements of this release.

121.0beta Firefox Beta

November 21, 2023

Version 121.0beta, first offered to Beta channel users on November 21, 2023

Firefox Beta gets updated 3 times a week and as a consequence, the release notes for the Beta channel are updated continuously to reflect features that have reached sufficient maturity to benefit from community feedback and bug reports.

Warning: Features listed here may or may not make a final release of Firefox.

In addition to these release notes, you can follow ongoing development via our @FirefoxBeta Twitter account.


  • Firefox now prompts Windows users to install the Microsoft AV1 Extension to enable hardware decoding support from about:support if not already installed.

  • Firefox now supports Voice Control commands on macOS systems.

  • Firefox now allows you to force-underline links in websites. This is useful for people with achromatopsia for example.

  • On Linux, Firefox now defaults to the Wayland compositor when available instead of XWayland. This brings support for touchpad & touchscreen gestures, swipe-to-nav, per-monitor DPI settings, better graphics performance, and more.

    Note that due to Wayland protocol limitations, Picture-in-Picture windows require an extra user interaction (generally right-click on the window) or a shell / desktop-environment tweak. See bug 1621261 for related discussion and tracking, this post for a KDE configuration, and this extension for GNOME.

  • Firefox now includes a floating button to simplify deleting drawings, text, and images added in PDFs.


  • The Firefox Debugger now includes a new feature: an option to disable the debugger; keyword on the current page. This feature is accessible via a new checkbox in the Breakpoints side panel, labeled Pause on debugger statement, located next to the existing Pause on exceptions checkbox. By default, this option is enabled, meaning that the debugger statements are active unless manually disabled.

    Screenshot of "Pause on debugger statement" toggle

Web Platform

  • The CSS text-indent property now supports the hanging and each-line keywords, offering more convenient paragraph layout for styles such as bibliographies, poetry, etc.

  • Firefox now supports text-wrap: balance, which can improve the appearance of short multi-line text blocks such as long headings or captions by harmonizing the line lengths.

  • Lazy loading iframes are now supported (<iframe loading=lazy>). Lazy loading iframes are only loaded when visible, so non-critical iframes can load later when needed to speed up initial page loads, reduce initial network usage, etc.

  • The :has() selector is now supported. This allows authors to match elements that has, or "anchors", at least one element matching its relative selector.

  • Support has been added for tail call elimination in WebAssembly language to improve support for functional languages.

Get the most recent version

All Firefox Beta downloads