Firefox is supposed to block autoplay of videos that have audio unless the user has clicked to play a video on the same page. There is definitely an arms race f

Firefox is supposed to block autoplay of videos that have audio unless the user has clicked to play a video on the same page. There is definitely an arms race for ads that find holes in the autoplay heuristics. You might try setting the about:config settings “media.autoplay.default” to 5 and/or “media.autoplay.blocking_policy” to 2: https://searchfox.org/mozilla-central/rev/e24277e20c492b4a785b4488af02cca062ec7c2c/modules/libpref/init/StaticPrefList.yaml#10434 https://searchfox.org/mozilla-central/rev/e24277e20c492b4a78... https://searchfox.org/mozilla-central/rev/e24277e20c492b4a785b4488af02cca062ec7c2c/modules/libpref/init/StaticPrefList.yaml#10421 https://searchfox.org/mozilla-central/rev/e24277e20c492b4a78... If you think there is a Firefox bug, you can file a bug report and link it to this autoplay bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1376321 https://bugzilla.mozilla.org/show_bug.cgi?id=1376321