end-of-life.org

Firefox 91 End of Life

Support dates and upgrade guidance — rebuilt from live data.

End of Life

Firefox 91 reached end of life on 20 Sept 2022. It no longer receives security fixes.

1,419 days without security patches
Recommended action: upgrade to Firefox 153.
Check your versionfirefox --version

Support timeline

Official dates from the Firefox release process.

MilestoneDateStatus
Initial release10 Aug 2021
End of life 20 Sept 2022 3.9 years ago
Latest release91.13.0 · 23 Aug 2022 final

Where to go from 91

Recommended target: Firefox 153.

The newest actively supported branch is Firefox 153 (latest release 153.0.3).

Frequently asked questions

Is Firefox 91 still safe to use?

Firefox 91 reached end of life on 20 Sept 2022, 1,419 days ago, and is no longer covered by standard support. Running it means no guaranteed security fixes.

Can I still download Firefox 91?

Yes — the final release (91.13.0) generally remains available from vendor archives and OS package mirrors, but installing it means running software with known, unpatched vulnerabilities.

What should I upgrade Firefox 91 to?

Upgrade to Firefox 153, the newest actively supported branch.

All Firefox versions