'''SUMMARY''' : I would like to disable all animations/twinkles/flickers/waves that indicate some elements inside a Web page are missing and are being loaded. I think all these "animations" make my computer lag. Hello, I would say that '''since Firefox 89, my browser has begun lagging''' like hell when it loaded some rich Web pages. And I have the impression it is worse with Firefox 107. When I'm saying Firefox lags, I mean it uses heavily my CPU (over 50%), and Firefox is almost unresponsive (for complex Web pages. For Wikipedia or Amazon, I don't have any trouble for example). '''I have to wait for Firefox to finish to load the full Web page and to display all elements before the usage of my CPU gets back to 1%'''. And it can take several minutes for some sites/pages. The problem doesn't come from my connection. And the trouble doesn't come from sites I'm visiting because once all elements are loaded Firefox is responsive. More precisely, for some sites, when I start loading the page, Firefox replaces missing (i.e not yet displayed/loaded) elements of the page with a rectangle of the same size of the element and each one of these rectangles are slightly flickering to inform me that AT THIS PLACE there is an element of the same size that is going to be displayed. When I'm saying "flickering" I could say it looks like a rectangle with a gradient of gray that is "waving" slowly. Sometimes it's a very light gray, sometimes a dark gray. It depends of the sites. And all these kind of "animations" are killing my computer. And I would like to totally disable these animations/twinkles/flickers/waves. For example, would it be possible to replace the color gradient animation with a static pink color ? I have a 10 years old laptop with iGPU (an Intel i5-2410M exactly) without discrete GPU. That doesn't help. I know. For me the trouble comes from there. But currently I can't afford buying a new laptop. I think all my drivers are up to date as my Ubuntu 20.04 is up to date. '''WHAT I'VE TRIED WITHOUT SUCCESS''' 1. I removed ‘.mozilla’ folder in my profile (i.e the folder that contains all addons and customizations) 2. Firefox in Safe Mode 3. I disabled hardware acceleration 4. I've tried [https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-or-cpu-resources Firefox uses too much memory or CPU resources] I really would appreciate your help because now, surfing on some sites becomes a big pain and I'm becoming mad (LOL). '''Thank you in advance :)'''