There's also setting "media.autoplay.default" to 1. None of that stuff works to turn off _all_ autoplay. The concerns about animated GIFs and javascript obfusc

There's also setting "media.autoplay.default" to 1. None of that stuff works to turn off _all_ autoplay. The concerns about animated GIFs and javascript obfuscated WEBMs and such only apply to sites that go out of their way to ignore the user's clearly stated preferences. If fighting that sort of thing mandates an arms war, this is a hill we should be willing to die on. Battle until the bitter end, until the rivers run red with blood.