: Navigate to the official Mozilla Archive for the version 78.15.0esr .
For users still running , finding a functional web browser is a common challenge as modern software requirements leave older systems behind. While the latest versions of Firefox are no longer compatible, you can still download and use a stable, legacy version to keep your Mac connected. The Best Version of Firefox for Mac 10.9.5
: Open Firefox from your Applications folder. You may see a warning that the app was downloaded from the internet; click Open to proceed. Important Limitations & Risks
Since the standard Firefox download page will automatically try to give you the newest (incompatible) version, you must use Mozilla’s archives:
: Once the .dmg file is downloaded, double-click it to open the installer window.