: When you open it for the first time, click "Open" on the security prompt that appears. Why Version 78.15.0?
: Navigate to the official Mozilla Release Directory for version 78.15.0esr. firefox mac 10.11 download
: Once downloaded, open the .dmg file and drag the Firefox icon into your Applications folder. : When you open it for the first
To download Firefox for Mac OS X 10.11 (El Capitan), you must use , as this is the final version compatible with your operating system. Newer versions of Firefox require macOS 10.15 or higher to function. Download Instructions for Firefox 78.15.0 ESR : Once downloaded, open the
Mozilla moved users on OS X 10.9, 10.10, and 10.11 to the cycle in June 2020 to provide critical security updates for as long as possible. Support for this version officially ended on October 5, 2021. Critical Considerations Install firefox for Mac IOS 10.11.6 - Mozilla Support
Since the official Firefox download page usually offers only the latest version, you must access the Mozilla archive to get the correct version for OS X 10.11: