Firefox Link Download For Mac 10105 Upd Direct

– this is the last version compatible with 10.10.5.

Check SHA-512 hashes available in the same directory ( .checksums file) to ensure integrity. firefox download for mac 10105 upd

Some users modify the Info.plist inside newer Firefox versions to trick the OS. as it causes crashes, missing symbols, and security holes. There is no community-maintained fork that backports security fixes to 10.10.5 as of 2026. – this is the last version compatible with 10

If you try to install a newer Firefox (version 100+), the installer will fail with an error: “You cannot use this version of Firefox with this version of macOS.” you must perform a manual install:

Since the automatic updater inside Firefox likely won't find the ESR version, you must perform a manual install: