Avoid third-party mirror sites which may bundle malware. Use the official Mozilla CDN (Content Delivery Network) to find direct DMG installers.
Mozilla recently extended security patches for Firefox 115 ESR on these platforms until August 2026 , giving users more time before an OS upgrade is mandatory. For macOS 10.9 through 10.11 (Mavericks to El Capitan) firefox legacy download mac
Users on these systems are automatically transitioned to the channel. Official Download: Visit the Mozilla Firefox ESR page. Avoid third-party mirror sites which may bundle malware
Firefox Legacy Download for Mac: A Complete Guide to Older Versions For macOS 10
Using legacy software comes with inherent risks. Keep the following in mind:
Compatibility depends entirely on your specific macOS version. Below are the most stable "end-of-life" versions for older systems: macOS Version Recommended Firefox Version Support Status Sierra, High Sierra, Mojave Firefox 115 ESR Security updates until August 2026 10.9, 10.10, 10.11 Mavericks, Yosemite, El Capitan Firefox 78.15.0 ESR End of Life (No more updates) 10.6, 10.7, 10.8 Snow Leopard, Lion, Mountain Lion Firefox 45.9.0 ESR End of Life (Unsupported) How to Download Official Firefox Legacy Versions
The final compatible version for these systems is . Direct Download Link: Firefox 78.15.0 ESR for Mac. Important Security Considerations