browserSettings.imageAnimationBehavior

A BrowserSetting object that can be used to change the way the browser handles animated images, such as GIFs.

The underlying value is a string that can take one of three values:

• "normal": the default. Play animated images as normal.
• "none": don't animate images at all.
• "once": play the animation once.

browser.browserSettings.imageAnimationBehavior.set({ value: "none" });