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.

99.0beta Firefox Beta

March 8, 2022

Version 99.0beta, first offered to Beta channel users on March 8, 2022

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.

New

  • You can now toggle Narrate in ReaderMode with the keyboard shortcut "n".

  • Linux: GTK overlay scrollbars are now enabled on Nightly and early betas

  • Added support for search with or without diacritics in the PDF viewer

  • The Linux sandbox was strengthened: processes exposed to web content no longer have access to the X Window system (X11).

  • Firefox now supports the Web MIDI API on Windows, macOS and Linux. Our implementation has some limitations such as lack of device hot-plug detection but should work with most existing web pages. A site-specific add-on is required to enable the API on your web page.

Developer

Community Contributions

  • With Firefox version 100 rapidly approaching, you can help test websites' compatibility with three-digit version numbers by enabling the new Firefox 100 User-Agent String option in the Experimental section of Settings (about:preferences#experimental). If you find a website that is broken with Firefox version 100, please file a bug report on webcompat.com.

Get the most recent version

All Firefox Beta downloads