Firefox 115 is the last version of the Firefox web browser that is compatible with several old versions of Windows or macOS. This affects Windows 7, 8, and 8.1, and macOS 10.12 to 10.14.

Any attempt to install Firefox 116 or newer on these devices is unsuccessful.

Support extension announced

Mozilla announced plans in July to extend support for these operating systems. Last week, it released the final version of Firefox 115 to the public. Mozilla did not mention a support extension for older systems at the time, which meant that users who used Firefox on these older systems did not know whether they would receive updates in the future.

Good to know:

• The Extended Support Release (ESR) allows users on these older systems to continue using Firefox.
• Mozilla's major competitors, Google and Microsoft in particular, have ended support for Windows 7 already.

Firefox ESR 115 is now replaced by Firefox ESR 128 for fully supported systems. This would have left users on older systems hanging, as they cannot install Firefox 128.

Now, there is official confirmation that support is extended.

Here are the details:

• Firefox 115 ESR support is extended until at least March 2025.
• In versions, it is supported until the release of Firefox ESR 115.21.
• Users get security updates for another six months at the very least.

Mozilla does not say if the extension is final or if there is a chance that support is going to be extended in March 2025 again for these systems.

The organization said that it is looking at usage numbers to determine whether it is extending support. Right now, about 10% of Firefox users use these older systems. The number goes down over time, as older systems do get replaced by newer ones eventually.

It is possible that Mozilla is going to extend support again in March 2025, if enough users are still using these systems.

Firefox users who run Firefox ESR 115 on devices with unsupported operating systems will receive updates automatically via the browser's built-in updating functionality.

Closing Words

About 10% of users are using unsupported operating systems. While the number has gone down significantly in the past couple of years, it is still a sizeable number for Mozilla.

The monthly active users have gone down ever since Google launched Chrome more than a decade ago. Mozilla recorded more than 200 million active users in 2021 for the last time. The number has gone down to about 160 million as of today. Other metrics, including daily usage, are going up, however.

Mozilla is working on reversing the usage trend and it appears that Google is helping to a degree. Google will end support for Chrome's old extensions system this year, which will make adblockers less effective on Chrome. It will also disable other extensions, all that are not updated by their developers or that cannot be upgraded.

While most Chrome users do not use extensions, it could drive some that do to Firefox, as the browser supports the old and the new extensions system going forward.

Firefox for Android got full support for browser extensions as well, which may persuade Android users to give it a try, as Chrome and Co. do not support extensions.

Do you run Firefox? What is your impression of the browser's development in the past year? (via Sören Hentzschel)