Download !!hot!! Firefox 12-51 52 Esr Jun 2026

Third-party download websites often bundle older software with malware, adware, or unwanted toolbars. The only safe way to acquire legacy Firefox builds is directly from Mozilla's official release archives.

: Click the .exe (Windows), .dmg (Mac), or .tar.bz2 (Linux) file to begin the download.

: Scroll through the numerical list to find your target version (e.g., 52.0esr or 45.0 ). Download Firefox 12-51 52 Esr

Downloading Legacy Firefox Versions: 12 through 51 and 52 ESR While Mozilla recommends using the latest version of Firefox

Once inside a version folder, you must choose the correct installer for your computer: : Scroll through the numerical list to find

Modern browsers have completely dropped support for NPAPI plugins like Adobe Flash, Microsoft Silverlight, and Java applets. Firefox 52 ESR was the final version to support these legacy web technologies.

Modern Firefox profiles are not backward-compatible with legacy versions. If you run a modern version of Firefox on the same machine, running an older version can corrupt your profile. Only download them for air-gapped machines

These versions have unpatched security vulnerabilities. Only download them for air-gapped machines, virtual machines, or specific legacy tasks. Do not use them for online banking or logging into modern social media.

Retained NPAPI plugin capabilities while the main release branch stripped them out.

Access the full directory of standard releases on the Mozilla Firefox Releases Archive.