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.
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.
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.