Firefox Legacy 67 Mac Download [verified] May 2026

Modern Firefox uses "downgrade protection." If you install version 67 over a newer version, it may refuse to open your existing profile. You may need to create a new profile to avoid data corruption.

Firefox 67 was designed for the macOS versions common in 2019. It remains a popular "legacy" choice because it was one of the last versions to support certain older Intel-based Macs before requirements were raised. Requirement macOS 10.9 (Mavericks) through macOS 10.14 (Mojave) Processor Intel x86 processor (Pentium 4 or newer with SSE2) Storage ~200MB of available disk space for installation Key Features of the Firefox 67 Release firefox legacy 67 mac download

This version introduced built-in blocking for cryptominers and fingerprinters in the Content Blocking settings. Modern Firefox uses "downgrade protection

Firefox will immediately try to update itself to the latest version. To stay on 67, you must go to Preferences > General > Firefox Updates and select "Check for updates but let you choose to install them" immediately after installation. It remains a popular "legacy" choice because it