So why not downgrade to the version you love? Because newer is not always bett. software downloads for old versions of programs, drivers and games. Firefox Mac OS X 10.9, 10.10 and 10.11 users move to Extended Support Release Install an older version of Firefox Switch to Firefox Extended Support Release (ESR) for personal use.While insecure versions of Firefox will continue to work on OS X 10.8 and earlier, using an up-to-date version of Firefox on a supported version of Mac OS will provide you with the best and safest. Note: If you have Mac OS X 10.7 (Lion) or 10.6 (Snow Leopard), you will need to download OS X El Capitan before you can upgrade to the latest Mac OS. This will provide security updates until the next ESR update in July 2021, after which the affected users will no longer receive security updates. These users will be moved to the Firefox Extended Support Release (ESR) channel by an application update. Get the Firefox Extended Support Release or Rapid Release browser for comprehensive data security and data protection.įirefox version 78 is the last supported Firefox version for Mac users of OS X 10.9 Mavericks, OS X 10.10 Yosemite and OS X 10.11 El Capitan.