Looking for older versions of Mozilla Firefox or the specialized 52 Extended Support Release? You can securely download these legacy browser versions directly from the official Mozilla Release Archive.
Backup Your Profile: Before installing an older version over a newer one, back up your profile data to prevent data loss or corruption. Download Firefox 12-51 52 Esr
Select Language: Open the en-US folder (or your preferred language code). Looking for older versions of Mozilla Firefox or
: Versions 51 and 52 ESR were released just before the "Quantum" update (Firefox 57), which transitioned exclusively to WebExtensions and dropped support for "Legacy" add-ons. Where to Download Download Firefox 12-51 52 Esr
Looking for older versions of Mozilla Firefox or the specialized 52 Extended Support Release? You can securely download these legacy browser versions directly from the official Mozilla Release Archive.
Backup Your Profile: Before installing an older version over a newer one, back up your profile data to prevent data loss or corruption.
Select Language: Open the en-US folder (or your preferred language code).
: Versions 51 and 52 ESR were released just before the "Quantum" update (Firefox 57), which transitioned exclusively to WebExtensions and dropped support for "Legacy" add-ons. Where to Download