I'm on 10.13 and the current version of Firefox works just fine. Download it and try. https://www.mozilla.org/en-US/firefox/all/#product-desktop-release

''<p>seanjp6482 [[#question-1372337|said]]</p>'' <blockquote>My Mac is quite old and only runs 10.'''11'''.6 OS can I get firefox to run on my Macbook </blockquote> Firefox since Fx '''79.0 and later''' including the current Fx 98 and Fx 91 ESR requires macOS '''10.12''' (ten.twelve) at minimum. Besides updating your OS to macOS 10.12 (ten.twelve) or later, the most current Firefox version you can install on macOS 10.'''11'''.6 is Fx '''78.15.0''' ESR though it is EOL with no more updates. https://support.mozilla.org/en-US/kb/firefox-mac-osx-users-esr https://www.mozilla.org/firefox/78.0/system-requirements/ https://www.mozilla.org/firefox/79.0/system-requirements/ https://www.mozilla.org/firefox/98.0/system-requirements/ '''In case you ever need the Firefox 78.15.0esr file. ''' https://archive.mozilla.org/pub/firefox/releases/78.15.0esr/mac/en-US/ other locales at https://archive.mozilla.org/pub/firefox/releases/78.15.0esr/mac/

''<p>jonzn4SUSE [[#answer-1492612|said]]</p>'' <blockquote>I'm on 10.13 and the current version of Firefox works just fine. Download it and try. https://www.mozilla.org/en-US/firefox/all/#product-desktop-release </blockquote> Not going to work for the OP as macOS 10.'''11'''.x is below the macOS 10.'''12''' minimum requirement since Fx 79.0 release.