Mozilla GFX Blog

AFAIK it's enabled by default in Nightly for some desktop Windows users. There's an about:config pref that others can use to enable it. Follow the WebRender blog for more information: https://mozillagfx.wordpress.com/

It's too bad the Mozilla Gfx blog is dead, I liked reading their updates on the graphics rendering subsystem: https://mozillagfx.wordpress.com/

The Mozilla Gfx blog regularly posts updates. They have been porting subsystems from servo to firefox, and making substantial progress on a regular basis. https://mozillagfx.wordpress.com

FYI, firefox is working on switching to rendering the entire page in opengl which should bring it's motion mark score up substantially. Details on that (and how to enable it in nightly at the bottom of each post) at https://mozillagfx.wordpress.com

The article about "Off-Main-Thread Painting (OMTP)"is an interesting read: https://mozillagfx.wordpress.com/2017/12/05/off-main-thread-painting/ Great to see so much effort being put into the fundamentals.

There's no ETA as far as I'm aware—it's mostly in the blocker bug burn-down phase and I don't want to try to predict when that will conclude. Progress is coming along quite nicely, and it's easier than ever to try it out in Nightly (just toggle gfx.webrender.all in about config). Lots of people on the team, including me, use it quite regularly. There's a newsletter you can check out too: https://mozillagfx.wordpress.com/

I don't know the ETA for WebRender in Firefox. The team is focusing on Windows first. You can follow WebRender development on the Mozilla Graphics team's blog: https://mozillagfx.wordpress.com/2018/01/16/webrender-newsletter-12/

I led the Stylo project to integrate Servo's CSS engine into Firefox as part of project Quantum [1]. I have the utmost respect for the engineers on the Servo team, and am sad to see them go (though I am certain they will have no shortage of opportunities as to what to work on next). Servo had two major roles within Mozilla - as an incubator for novel browser technology we wanted to ship in Firefox, and more recently, as a lighter-weight vehicle for Mixed Reality products. The latter has been the focus for the last three years, and those products now appear to be winding down. But the former was a huge success - both Servo's parallel CSS engine and its GPU-based graphics layer are now shipping in Firefox. While it seems unlikely that Mozilla will continue to prototype things in Servo, we're still building lots of innovative technology (and writing lots of Rust code) directly in Firefox. A few of the teams have blogged recently about the work they're doing [2] [3], and I'd encourage anyone interested to check it out. The Servo team accomplished a ton and left its ongoing mark on the Web. These changes are tough for everyone within Mozilla, but are not indicative of any change in strategy for Firefox. Gecko is alive and well, and there are no plans to switch to Blink. [1] https://bholley.net/blog/2017/stylo.html [2] https://mozilla-spidermonkey.github.io/blog/ [3] https://mozillagfx.wordpress.com/

You may be thinking of Core Animation usage, which is really good to see. As I understand it this is also a prerequisite for WebRender. The bug in question: https://bugzilla.mozilla.org/show_bug.cgi?id=1429522 A blog post breakdown: https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power… This does make a difference, but macOS is in many respects a "death by a thousand cuts" platform due to the UI/UX bar being fairly high. It notably clips in many areas where Chrome and Safari simply don't, which leads to a jarring experience. Scrolling and resizing is still not smooth, even after tweaking it behind the scenes - although to be fair, the post above calls out that they're aware they can make this smoother with CA. Firefox on macOS also still has issues with hardware acceleration. Comparing the following URL across browsers I can achieve 60fps, no drops, on Safari. Firefox on my Mac averages 45fps. https://webglsamples.org/aquarium/aquarium.html I love Firefox (and the associated lineage) - I really do. I've kept it installed since the Mozilla Suite days. I still check every damn release to see if I could switch back. I'm sad every time I find I can't.

We're currently rewriting most of the graphics rendering of Firefox (with what is called the WebRender project). This is the first time Linux users will have hardware accelerated rendering by default, and is a pre-requisite to take real advantage of hardware-accelerated video decoding. It's enabled on some configuration in Nightly builds [0], and it's being worked on actively. If you want to know more, the graphics teams has a blog where updates are periodically posted about what is happening, often with interesting insight about the innards of a web browser rendering stack [1]. Once rendering is hardware accelerated, it makes sense to look into hardware video decoding. Doing hardware video decoding without hardware rendering roughly means we need to read back from GPU memory into main memory, composite the image in software, and then upload back to the GPU to display, which is super super inefficient. [0]: https://wiki.mozilla.org/Platform/GFX/WebRender_Where [1]: https://mozillagfx.wordpress.com/

Firefox and Gecko has a lot of tech debt, and it's big. It'd be too risky to just try to throw big chunks of it out and hope that the replacement will be great. Though the momentum seems lost, the WebRender integration is still ongoing. ( https://mozillagfx.wordpress.com/2018/11/29/webrender-newsletter-32/ ) And it's big, it's complex, it's hairy, the web is a mess. So, it's slow and full of terrors. (Shaders, caching, multi-threading, mobile, multi-core, C++ and Rust interfacing, etc.) The next thing seems to be Fission, which is the continuation of the e10s (electrolysis) content process model into full/more Site Isolation. ( https://wiki.mozilla.org/Project_Fission - but it seems hard as fuck: https://mail.mozilla.org/pipermail/firefox-dev/2018-July/006628.html nowadays they seem to be stripping out the old Gecko XUL stuff and replacing it with something newer and better: https://mail.mozilla.org/pipermail/firefox-dev/2018-November/006903.ht… )

WebGPU is coming. They shipped Windows support a few months back. https://mozillagfx.wordpress.com/2025/07/15/shipping-webgpu-on-windows…

It's almost there: firefox has shipped it for windows (to begin with): https://mozillagfx.wordpress.com/2025/07/15/shipping-webgpu-on-windows… And safari is coming soon. So not too long untill it'll be usable.

Your web browser may have also spent some time packing rectangles into rectangles. I recall reading this article a while back about how Firefox does/did it. https://mozillagfx.wordpress.com/2021/02/04/improving-texture-atlas-al…

They've mentioned it without saying directly that that's what they've done. > And on Linux, we’ve improved WebGL performance and reduced power consumption for many users. It links to a page with some more info[0]. Exiting stuff. [0] https://mozillagfx.wordpress.com/2021/10/30/switching-the-linux-graphi…

> And on Linux, we’ve improved WebGL performance and reduced power consumption for many users. All right! > Users of the proprietary Nvidia driver will need to wait a little bit longer as the currently released drivers lack an important extension. [1] Oh no :( [1]: https://mozillagfx.wordpress.com/2021/10/30/switching-the-linux-graphi…

It's hilarious how a macOS-lookalike desktop environment is using Linux-like technologies like Openbox and KWin, rather than building something in Cocoa. I suspect it will cause trouble trying to bodge KWin to have Mac-like window management, or support apps that integrate with Apple's graphical acceleration and compositing frameworks (Core Animation? https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…

One thought, cant one reason to the difference when you checked be that Firefox is the active application and have focus? And do you maybe have any addons in Firefox? Extensions can give bigger energy impact, you can check that under about:performance. Anyways I think both have low energy impact even if safari happens to be abit lower. Personally I use Firefox on mac and can many times have 100+ tabs and it works without any problems. It could also be mention that Firefox now use macos coreanimation that drastically improved Firefox battery performance [1]. So give it a real test again, Firefox is really awesome and needs all support :) We need bigger diversity among webbrowsers, not just chromium based. [1] https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…

I'm a FF user on macOS, but it is a power hog. They have been working on it for some time: https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…

They have, it's suspected to be caused by a race condition with memory pressure events [0][1]. It looks like the patch is not included in Firefox 74 though. [0] https://mozillagfx.wordpress.com/2020/03/02/moz-gfx-newsletter-51/ [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1617083

Firefox switched to CoreAnimation in v70, which made a big difference. https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…

Yea they fixed it: - https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power… - https://www.zdnet.com/article/upcoming-firefox-update-will-decrease-po… Give it a go again!

> With FF, even using ublock and even a pihole, the fan was constantly at full throttle. Is that still the case even with FFs recent update to version 70[1]? [1]: https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…

Did it not get better with FF 70 for you? They switched the rendering to use a better API on MacOS: https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…

By using undocumented MacOS private APIs, which bolsters his point. On OSes that don't have this issue, other browsers perform better on the same hardware. https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power… This has been going on since WebKit launched with no effort from Apple to clean it up, so it certainly seems intentional. http://archive.is/MtntN

They are now because they both use those APIs. You can read about the impact of this specific one here: https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power… Before using those private APIs, with no other options to reach the same performance as Safari, both Chrome and Firefox were in a completely different league.

“On macOS” is the important part. Safari is by far the most battery friendly browser there and quite possibly has significant market share too. Mozilla has recently managed to reduce their consumption significantly using these APIs: https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…

Mozilla recently published a good write up on why they started using these undocumented CALayer API's in Firefox 69. The TLDR is that that these private API's allowed them to get up to 3x better battery usage in Firefox. The article also mentions that Chrome uses these same Core Animation API's. https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…

See https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power… More work is planned to reduce the energy usage for scrolling and full screen video. Though I guess for your example you don't watch things fullscreen.

More details on the mac improvements https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power…