Mozilla Firefox 91.0.2 / 91.0.1 ESR

Fixed

• High Contrast Mode is no longer enabled by default when "Increase Contrast" is checked in macOS settings (bug 1726606)

• Firefox no longer clears authentication data when purging trackers, to avoid repeatedly prompting for a password (bug 1721084)

Fixed

• Fixed an issue causing buttons on the tab bar to be resized when loading certain websites (bug 1704404)
• Fixed an issue which caused tabs from private windows to be visible in non-private windows when viewing switch-to-tab results in the address bar panel (bug 1720369)
• Various stability fixes

• Security fix

New

• Building on Total Cookie Protection, we've added a more comprehensive logic for clearing cookies that prevents hidden data leaks and makes it easy for users to understand which websites are storing local information. Learn more
• Firefox now supports logging into Microsoft, work, and school accounts using Windows single sign-on. Learn more
• The simplify page when printing feature is back! When printing, under More settings > Format select the Simplified option when available to get a clutter-free page. Learn more
• HTTPS-First Policy: Firefox Private Browsing windows now attempt to make all connections to websites secure, and fall back to insecure connections only when websites do not support it. Learn more
• We've added a new locale: Scots (sco)
• The address bar now provides Switch to Tab results also in Private Browsing windows.
• Firefox now automatically enables High Contrast Mode when "Increase Contrast" is checked on MacOS

Fixed

• Various security fixes

Enterprise

• Various bug fixes and new policies have been implemented in the latest version of Firefox. See more details in the Firefox for Enterprise 91 Release Notes.

Developer

• Developer Information

Web Platform

• The Visual Viewport API is now supported on desktop platforms