[nvarsj]

Firefox has always been unbearably slow on Linux for me. It's the main reason I swapped to Chrome in the first place. I tried switching back to Firefox about 6 months ago, same problem of extremely slow and laggy UI. Interesting to hear 57 is faster now, it may be worth trying again.

[JoshTriplett]

Do you have any extensions installed?

Have you tried using a fresh profile, just to narrow the possible variables?

If you've checked both of those things, and you can characterize the slowness in the context of specific operations (e.g. what "laggy" means, precisely), then I'd recommend filing a bug and working with the developers to track down the problem. Because that is not normal.

[fmoralesc]

Also, current Firefox has `about:performance`, where you can diagnose what addons and tabs can be slowing down the browser. It's quite neat.

I just refreshed my profile and performance improved immensely.

[ac29]

Go to about:config and set layers.acceleration.force-enabled to true. Made a dramatic difference for me in Linux using a Intel iGPU.

You can check the acceleration status in about:support, look at HW_COMPOSITING and OPENGL_COMPOSITING.

[cpeterso]

Firefox 57 should be a much, much improved experience. e10s with multiple processes started rolling out to users in Firefox 54 and tons of small performance issues have been fixed in 55-57.

On Linux, manually enabling GPU acceleration as user ac29 describes below can a big difference. Unfortunately, a lot of Linux GPU drivers have issues that prevent acceleration from being enabled by default for some users.

[djsumdog]

Same here, it's why I switched to Vivaldi. I had to restart Firefox every day or so and it still lagged. I've read the other recent post on here that shows 100+ tabs has almost no startup burden in FF57 compared to previous builds. I should try it again.