Firefox version 115 will be the last supported Firefox version for users of macOS 10.12 (Sierra), macOS 10.13 (High Sierra) and macOS 10.14 (Mojave). If you are using these versions of macOS you will be moved to the Firefox Extended Support Release (ESR) channel by an application update. Mozilla will provide security updates for these users until September 2024. No security updates will be provided after that date.
Why has Firefox ended support for macOS 10.12, 10.13 and 10.14 users?
While Apple doesn’t have an official policy governing security updates for older macOS releases, their ongoing practice has been to support the most recent three releases. The last security update for macOS 10.14 was in July 2021. Unsupported operating systems receive no security updates and have known exploits. With no official support from Apple, maintaining Firefox for obsolete operating systems becomes costly for Mozilla and dangerous for users.
Can I still browse safely with Firefox macOS 10.12, 10.13 or 10.14?
Mozilla is providing critical security updates through the Firefox ESR channel up until the end of ESR version 115, September 2024. After this, no security updates will be provided and you are strongly encouraged to move to a supported version of macOS.
How can I get the newest features of Firefox?
If you want to keep your Firefox up to date, with all the latest features and updates, you need to upgrade your operating system to macOS 10.15 or higher. In some cases, Apple may require newer hardware in order to support the newer operating system. After upgrading, users can easily reinstall Firefox and keep all of their settings.