Here's a small clip illustrating it (please give it a look): https://gfycat.com/WetPointedAngora Edit: Another one demonstrating it much better: https://gfycat.com/MelodicCourageousBighorn The curious thing is that the site's framerate counter shows similarly high values on both, but the framerate is visibly way worse on Firefox. Tested against Chrome, both using the same GPU and similar Add-Ons and open tabs. Multiprocess is enabled. The issue also happens when tested individually and also with all add-ons disabled. That is not the only website with the problem, it also happens on Google Maps and pretty much anything that uses WebGL. Firefox 55.0.2, Windows 10 Creators' Update, both 64-bit, GPU is an Nvidia GTX 950M (it runs just as bad on the CPU's IG). The hardware should be more than capable to perform well, so I think that is not the issue.