Firefox 63 will have much-needed performance improvements on macOS

Mozilla has released Firefox 62 with some minor updates like support for macOS Mojave’s automatic theme switching, a new Firefox Home tab page, support for variable fonts and more. However, for macOS users, the next release, Firefox 63, is the one to look forward to. It is going to include some much needed performance improvements for macOS users, which will improve tab switching and overall graphics usage. This should result in a better experience for macOS users who have been complaining about Firefox’s performance issues since a long time, which weren’t fixed even in Firefox Quantum’s initial release.


Firefox 63 for MacDespite the much hyped Firefox Quantum release, the performance for Mac users was not as good as expected. Windows users were able to enjoy the faster performance, but for Mac users, the browsing experience has been slow. Jittery scrolling, slow tab switching and slideshow like frame-rate when watching videos or using graphically heavy websites were common issues. Reddit is filled with complaints about battery drain and over-heating MacBooks when using Firefox Quantum.

Some of these issues were attributed to the fact that Firefox did not use CoreAnimation, Mac’s API for talking to the GPU, which made it inefficient. It doesn’t matter whether the Mac had internal or dedicated graphics, the issue could be replicated on both slow and powerful Macs, as long as they used a Retina Display. When visiting a graphically heavy website, watching high quality videos or WebGL based web apps, performance used to take a massive hit. ¬†This issue has been fixed and you can read more details here. Another issue was the lack of ‘tab warming‘¬†which was released for Windows and Linux with Firefox 61. This feature is what improves tab switching performance. You can read more about it here.

If you want to go ahead and test Firefox 63’s performance improvements on your Mac, you can download Firefox beta. Otherwise, you can wait until 23 October, when Mozilla is expected to release version 63 to stable channel i.e. all users. Having used Firefox 63 nightly on my 12″ MacBook, I can confirm that the improvements make a noticeable difference. However, there is still some work to be done before Firefox can feel as fast as Safari or Chrome on Mac.

While Firefox is working towards improving things for macOS users, Chrome seems to have reversed course recently. With the newest Chrome 69 release, macOS users have been greeted with a sluggish UI, slow tab switching and overall laggy performance. This is not why users preferred Chrome over other browsers, so hopefully Google will be working on fixing these issues in upcoming updates.