Many sites¹ immediately start playing videos as soon as a page loads.

I never want this. I’ll often open a handful of links in new tabs, hear a video playing, mutter under my breath, track it through the forest of new tabs, pause it, then try to find my way back to where I was.

After suffering under this onerous burden for literally years, I learned that it’s incredibly easy to fix! Just set this flag in Firefox’s about:config:

media.autoplay.enabled = false

Ta-da! A dramatic improvement. Videos now start playing only when I tell ’em to, as God and Sir Tim Berners-Lee intended.