Because of the popularity of Flash, animated GIFs have become a thing of the past. However, I still see quite a number of site featuring them. And I see a lot of forums avatars still using animated GIFs. Personally, I find them annoying most of the time. If you’re annoyed by animated GIFs too, you just might want to shut the animation down.

A quick way to stop animated GIFs is to press Esc as soon as the page stops loading. To shut it off animated playback permanently, do the following steps:

• Access the about:config page.
• Find the image.animation_mode preference name
• Double-click on it to change the string value to none
• Close the about:config page/tab
• The changes take effect instantly

Via: Digital Inspiration