Mozilla Firefox To Ditch Direct3D 11 And Shift Entirely to WebRender Engine with Firefox 92/93

You can no longer revert back starting from Firefox 93.

Mozilla introduced their WebRender rendering engine in Firefox two years ago in 2019. While it has always been an optional toggle in Firefox’s settings, that privilege is going away real soon. Starting with Firefox 93, WebRender will become the default and only rendering engine available in the browser. Direct3D, which had previously been the default, will now be completely removed.

Firefox 91 (latest version available) running on Direct3D rendering engine. [See “Composition”]

What Is WebRender?

For those of you who don’t know, WebRender is a 2D rendering engine that utilizes your graphics chip to accelerate the performance of Firefox. It’s similar in workings to the contemporary Direct3D engine, only that it’s better as it internally uses OpenGL API. WebRender basically makes the pages load faster and the whole browser feels a lot smoother to navigate. There is no inherent downside to WebRender, apart from it being unstable at launch and causing issues on extremely low-end hardware.

Firefox 91 running on WebRender engine. [See “Composition”]
WebRender saw a gradual rollout from Mozilla with it first appearing on Windows on Firefox 67 in 2019. Since then, it has made its way over to MacOS in Firefox 87, Linux in Firefox 91, and with Firefox 92, it will ship to the only platform left, Android. With WebRender being available on Android, all platforms are now covered and Mozilla’s long-term goal to eventually make WenRender the platform-wide default is finally a reality.

WebRender Is Your Only Option Going Forward

But, Mozilla is going one step ahead and on top of now shipping WebRender on all devices and making it the default, it is completely removing Direct3D and the option to switch back to it. Firefox 93 will remove the gfx.webrender.force-legacy-layers¬†preference, making it impossible to fallback on layers. Furthermore, the environment variable MOZ_WEBRENDER=0 that does essentially the same thing will also be rendered (no pun intended) ineffective in Firefox 93 and going forward. Unless gfx.webrender.software is set to true, you’ll get either HW-WR or SW-HW and MOZ_WEBRENDER=1 depending on your specific hardware configuration.

Source: Mozilla Wiki

Firefox 92 will launch on September 7th and will be succeeded by Firefox 93 soon after. Firefox 92 will solidify WebRender as the default and the next version will hammer that in further by taking away the option to disable WebRender. And, while this may sound really anti-consumer, it’s not. WebRender is objectively a better rendering engine and it’s been a long time since it debuted. By now, it’s stable and doesn’t bring up any issues for users. So, if anything, the full shift to WebRender is a good thing as Firefox had always been building up to this since 2019.

Huzaifa Haroon
Born and raised around computers, Huzaifa is an avid gamer and a Windows enthusiast. When he's not solving the mysteries of technology, you can find him writing about operating systems, striving to inform the curious.