Alternatives to Firefox ESR

The Extended Support Release of Firefox, a long-term stable build intended for organisations. The listings below can replace it for an important use case. Each note says what changes if you switch.

Replacements

Listings that take over the same core job as Firefox ESR.

  • Firefox

    The main browser not built on Chromium, with tracking protection turned on by default.

    FreeOpen sourceWindowsmacOSLinuxAndroidiOS

    Firefox is the regular release of the same browser, getting new features sooner and adding Android and iOS builds, but it changes faster than the long-term stable ESR.

  • Microsoft Edge

    Microsoft's Chromium-based browser, bundled with Windows.

    FreeProprietaryWindowsmacOSLinux

    Microsoft Edge moves managed deployments to a proprietary Chromium browser bundled with Windows that runs Chrome extensions, while pushing Bing and Microsoft accounts.

  • Google Chrome

    Google's browser, the Chromium-based one most web development is tested against.

    FreeProprietaryWindowsmacOSLinux

    Google Chrome switches to a proprietary Chromium browser with updates every four weeks and the largest extension library, tied closely to Google account and advertising systems.

  • Waterfox

    A Firefox build with telemetry stripped out, ad blocking and encrypted DNS turned on from the start.

    FreeOpen sourceWindowsmacOSLinux

    Waterfox keeps Firefox extensions and profiles working, removes telemetry and enables ad blocking and encrypted DNS, but a small team ships security updates after Firefox.

  • LibreWolf

    A Firefox build with the privacy settings already turned up and uBlock Origin included.

    FreeOpen sourceWindowsmacOSLinux

    LibreWolf keeps the Firefox base with privacy settings raised and uBlock Origin included, but its aggressive defaults break some sites and log you out whenever you close it.

  • Mercury

    A Firefox fork with compiler optimizations and privacy patches taken from LibreWolf, Waterfox and GNU IceCat.

    FreeOpen sourceWindowsmacOSLinux

    Mercury is a compiler-optimized Firefox fork with privacy patches and a portable variant, but a single developer maintains it and updates can trail official Firefox releases.

Also worth comparing

These listings name Firefox ESR as their own alternative, so the relationship runs both ways.

  • Basilisk

    Non-Chromium browser from the Pale Moon ecosystem that keeps XUL extensions.

    FreeOpen sourceWindowsmacOSLinux

    Firefox ESR is Mozilla's slow-changing long-term release with current security support, but it runs modern web extensions rather than classic XUL add-ons.

  • Pale Moon

    Independent Firefox fork with the classic interface and XUL extension support.

    FreeOpen sourceWindowsmacOSLinux

    Firefox ESR is a slow-changing long-term Firefox release with current security fixes, but it uses modern extensions instead of the XUL model.

  • SeaMonkey

    Classic internet suite combining a browser, email, feed reader, IRC client and HTML editor.

    FreeOpen sourceWindowsmacOSLinux

    Firefox ESR offers a slowly changing, long-term supported Firefox with group policy templates and a newer engine than SeaMonkey, but no integrated mail, news or page editing.

  • Supermium

    A current Chromium-based web browser that runs on Windows XP, Vista, 7, 8.x and later.

    FreeProprietaryWindows

    Firefox ESR is an open-source, long-term stable Firefox that remains available for older operating systems, switching from Chromium to Gecko with slower feature changes.

Similar software

Related functionality, not a direct replacement.