Download Firefox 12-51 52 Esr [2021] May 2026

To download legacy or Extended Support Release (ESR) versions of Firefox, such as version 52, you should use official Mozilla archives to ensure security and file integrity. Older versions like 12–51 are generally outdated and no longer receive security updates, so they should only be used in isolated or legacy environments. 🌐 Direct Download Links

• Copy your profile folder (bookmarks, passwords, extensions) before downgrading or switching between major releases.

Quick Download Instructions (Windows Example)

Using archive.mozilla.org:

Step 4: Download the Language Pack

Select your language (e.g., en-US). Download the installer file ending in .exe (for Windows) or .dmg (for Mac). Download Firefox 12-51 52 Esr

Download the Installer: Click the .exe (Windows), .dmg (Mac), or .tar.bz2 (Linux) file to begin the download. To download legacy or Extended Support Release (ESR)