How do I update Firefox to the newest version. I'm trying to access a website I've used in the past and it is telling me to update my browser. Can you help?

Hi Mike

Firefox is no longer supported on the version of macOS that you have installed. Both the operating system and Firefox on your device are no longer getting security and stability updates.

I recommend that you consider moving to a more up to date operating system that can support a modern copy of Firefox (and likely other software that you use).

For the old eol macOS 10.9, 10.10, 10.11 the last version to support was Firefox 78.15.0esr.

For Firefox 79.0 to 115 ESR you need macOS 10.12, 10.13, 10.14 at minimum to run and Firefox 116.0 to current versions you need macOS 10.15 at minimum to run.