Download High Quality Firefox Mac 10.11 [Cross-Platform]

Because the official Firefox download page automatically offers the newest version (which will not run on 10.11), you must use the archived directory:

If you are looking to download Firefox for Mac OS X 10.11 (El Capitan), you must download . This is the absolute final version compatible with El Capitan. Newer versions, including standard Firefox and later Extended Support Releases (ESR), require macOS 10.12 or higher. Step-by-Step Installation Guide download firefox mac 10.11