Download Exclusive Firefox For Mac Os X Yosemite 10.10.5 May 2026

Go to the official Mozilla CDN for the Firefox 78.15.0esr release.

Click on Firefox 78.15.0esr.dmg to begin the download. download firefox for mac os x yosemite 10.10.5

Open Firefox from your Applications folder. You may see a warning that the app was downloaded from the internet; click Open to proceed. Important Compatibility Details Go to the official Mozilla CDN for the Firefox 78

Since the standard Firefox Download Page will typically offer the newest version (which is incompatible with Yosemite), you must manually download the legacy version from Mozilla's archive: You may see a warning that the app

If you find that Firefox 78 ESR is too slow or incompatible with modern sites, consider these options: How to update outdated browser on OS X Yosemite

The last version of Firefox officially supported for is Firefox 78.15.0 ESR . Because newer versions of Firefox require macOS 10.15 or later, users on Yosemite must use this legacy Extended Support Release (ESR) to maintain compatibility. How to Download Firefox for OS X 10.10.5

This version is specifically designed for Mac users on OS X 10.9 (Mavericks), 10.10 (Yosemite), and 10.11 (El Capitan).