PSA: try turning on WebRenderer in Firefox

This is a new rendering backend for Firefox that’s not yet on by default. Presumably there are some edge cases where it makes things worse or causes some instability, but so far I have not experienced anything bad. On the contrary, without it, I and some other people get terrible flickering in Firefox on Wayland. With it enabled, not only is the flickering gone, but scrolling performance becomes buttery smooth and CPU usage decreases noticeably on both Wayland and X11, resulting in increased battery life! Win-win-win.

To turn it on, visit the about:config page in Firefox, search for “gfx.webrender.all”, and set it to true. That’s all there is to it!

21 thoughts on “PSA: try turning on WebRenderer in Firefox

  1. Hi Nate, is the CPU usage decreasing just your “feeling” or we could measure it somehow?
    Even if it’s feeling, I wonder what is the test case to feel it too 🙂
    Didn’t try to switch, though.


    1. I could probably measure it but I don’t think that would be a good use of my time. Anecdotally, things that were laggy before–especially scrolling in a maximized window– no longer are.


        1. It was laggy on virtually every page when the window was maximized and while using the energy saving performance mode, manually set using I suspect this is also related to having more pixels to push with a 4k screen.

          With WebRenderer, scrolling is smooth as sin with everything else the same. 🙂


          1. Thanks for giving the details. Didn’t try tinkering with the performance mode, but if it related with 4k it will be hard to note for me as I don’t have such equipment.
            FWIW don’t see any difference on Gnome Wayland so far..

            Liked by 1 person

      1. From a personal standpoint I prefer clear language and when I read “and CPU usage decreases noticeably” I thought you of course had looked at it at KSysGuard or some other graphs, else I would not write such things mostly backed by speculation, since this is how rumors start. Or have you actually looked at it and this is a misunderstanding?


  2. Really nice advice Nate, I happened to have it activated already (I think I activated about 1 year ago or so, because I don’t remember it exactly right now), but yeah, pretty nice to use the newest Firefox’s technologies :).

    Bests as always Nate ^^.

    Liked by 1 person

  3. Nice one, Nate! Almost forgot about it, since I last checked it matured quite a bit. It’s a super smooth enhancement. One more Rust component to the rescue \o/

    Liked by 1 person

  4. Under Wayland with Webrender you can have/can enable video hw accel, further increasing efficiency/battery life ( check vaapi flags in about:config ).
    It will come to X11 eventually


      1. Firefox never had working hw accel on Linux [ with the exception of flash ] it was all in software, same with chromium for that matter ] unless the chromium is patched ]
        You might be not recalling it correctly.


  5. > With it enabled, not only is the flickering gone, but scrolling performance becomes buttery smooth and CPU usage decreases noticeably on both Wayland and X11, resulting in increased battery life! Win-win-win.

    Thanks for the tip! But if you additionally use a general content blocker, like uBlock Origin, you can enhance both performance and the battery life significantly even more. 🙂

    Liked by 1 person

  6. Unfortunately the performance is still terrible compared to Windows. Slower scrolling with much more stutters…


  7. It’s very hardware specific. Most systems benefit from this feature, however I’ve recently switched from Lenovo T460p (Intel UDH 530) to Lenovo P1 gen2 (Intel UHD 630) and enabling web-render slows things down. Back when it was just introduced few years ago on a GTX1060 system it was about 50% boost in performance, but it wasn’t stable enough.


  8. I’m running on a truely ancient Core 2 Duo Laptop from circa 2008, and the difference WebRenderer makes is truely drastic.

    Stuttering 720p Video Playback has turned into Smooth 1080p Video Playback which was impossible without HW.
    Page Rendering is Instant instead of Elements popping up over the course of a few seconds.

    It should be Default by now IMO. Haven’t had any issues with it at all, and this is over the course of 6 months.


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