end-of-life.org

Firefox 139 End of Life

Support dates and upgrade guidance — rebuilt from live data.

End of Life

Firefox 139 reached end of life on 24 Jun 2025. It no longer receives security fixes.

468 days without security patches
Recommended action: upgrade to Firefox 157.
Check your versionfirefox --version

Support timeline

Official dates from the Firefox release process.

MilestoneDateStatus
Initial release27 May 2025 1y 4mo ago
Security Support ended24 Jun 2025 1y 3mo ago
Latest release139.0.4 · 10 Jun 2025 final

Where to go from 139

Recommended target: Firefox 157.

The newest actively supported branch is Firefox 157 (latest release 157.0).

Frequently asked questions

Is Firefox 139 still safe to use?

Firefox 139 reached end of life on 24 Jun 2025, 468 days ago, and is no longer covered by standard support. Running it means no guaranteed security fixes.

Can I still download Firefox 139?

Yes — the final release (139.0.4) 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 139 to?

Upgrade to Firefox 157, the newest actively supported branch.

All Firefox versions