I am running Firefox 66.00.05 on Windows 10 Pro v 1803. I would like to prevent videos from auto-playing, but I am unable to work out how to do so. I have checked "Block websites from automatically playing sound" in options, which doesn't do anything, they still play and the sound is still on. (Also, even if this works, I want to be able to stop it playing the video at all, not just playing the video without sound). I have also set the following values in about:config (although I understand this is obsolete), but it doesn't prevent autoplaying: media.autoplay.default: 1 media.autoplay.enabled.user-gestures-needed: false media.autoplay.allow-muted: false Can someone help me turn off autoplay?