How can I disable animations in Firefox when going full screen?

In the newest versions of Firefox:

  1. Open the about:config website
  2. Set toolkit.cosmeticAnimations.enabled to false

Tested on:

  • Firefox 57.0b9 (32-bit) from the Debian experimental branch running on Debian testing (buster)
  • Firefox 56.0 (64-bit) running on Ubuntu 17.10
  • Firefox 68.0 (64-bit) running on FreeBSD 13.0-CURRENT

References

  • about:config browser.fullscreen.animateUp has no effect (support.mozilla.org)
  • All the other the resources I found on the Internet were outdated (they suggest modifying options in about:config, which no longer exist).