: Firefox version 78 was the last to support OS X 10.9 Mavericks, 10.10 Yosemite, and 10.11 El Capitan. Security Status : Support for this version ended in October 2021
Follow these precise steps to safely download and install the compatible version of Firefox on your legacy Mac. Step 1: Download the Correct Installer firefox download for mac 10105 upd
and drag the Firefox icon into your Applications folder . : Firefox version 78 was the last to support OS X 10
:Access the official Mozilla archive to download the compatible installer directly: Download Firefox 78.15.0esr (English US). firefox download for mac 10105 upd
The safest method is to visit the Mozilla Archive and download the .dmg file for your language (e.g., en-US ).