Apple no longer supports OS X Yosemite, but Mozilla has historically provided extended support releases (ESR) for older Macs. This article will walk you through exactly how to find, download, install, and troubleshoot , ensuring you get the final secure update available.
If prompted to replace an existing version of Firefox, click . Key Technical Specifications
Note: You can replace en-US with your local language code (e.g., fr , de , ja , zh-CN ). firefox download for mac 10105 upd
, which remained supported with security updates much longer.
Many Mac users find themselves in the situation where their hardware cannot be upgraded to a newer version of macOS beyond Catalina. If you are using an older Mac that is limited to macOS 10.15, you can rest assured that Firefox will still support your operating system for the foreseeable future. Mozilla has made a commitment to maintaining compatibility with Catalina, giving you access to the latest security updates, privacy features, and browser innovations. Apple no longer supports OS X Yosemite, but
in about:config → set to 10 (reduces RAM use).
: If your browser says it is up to date but websites aren't loading correctly, it is likely because the internal certificates of version 78 are expired. Alternative Options Key Technical Specifications Note: You can replace en-US
ESR stands for . This is a version of Firefox intended for schools, universities, and businesses that need a stable browser for longer periods. While standard Firefox updates every few weeks with new features, ESR updates less frequently and focuses strictly on security patches.
Once you’ve completed the , speed up your legacy Mac:
If you are looking to update your browser, .
: Once the download finishes, double-click the Firefox 78.15.0esr.dmg file.