hi, in firefox 63 the autoplay preferences are reorganised in preparation for this feature shipping out of the box in one of the upcoming versions. in about:config you can set media.autoplay.default to 1 in order to block automatic playback on all pages or set it to 2 to decide on a per domain basis.

Thank you for your quick response but your answer does not address the problem. My options for media.autoplay.enables are True or False, as I stated in my question. I set it to false months ago and the videos did not start automatically. Today I installed a Firefox update and the False setting is now ignored and videos start automatically. I don't want that. It is annoying. Whoever thought that was a good idea should be punched. How do I fix the actual problem?

my answer did address the question. the undocumented media.autoplay.enabled pref is no longer in use. set media.autoplay.default to 1 instead to get the exact same behaviour. in an upcoming version of firefox this will also be an option that is surfaced directly within the browser preferences ui.

1 is not an option. True is. False is. It is set to false but the videos still start. If you are saying to set it to true, that is the opposite of what I want. It is set to False and the videos are starting anyway after today's update. How do I fix that?

we are talking about separate preferences. it's media.autoplay.default you'll want to edit from this point onwards.

I see. Sorry about that. Thank you for your help. It is now working correctly.

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