Firefox has it, too. The UI is missing, but you can toggle it in about:config.
image.animation_mode none
Thanks for this!
Thanks, I set it up now, does anyone know if you can do the same in Chrome/Chromium without extensions?
Chrome was one of the last to actually implement this feature. It took 8 years (!), and Animation Policy (part of the accessibilityFeatures api) still doesn't work that great, and is only available via extensions.