&gt;a bug in YouTube&#x27;s compatibility-autodetection caused it to fall back to a slower<p>I double it&#x27;s a bug, it&#x27;s not the first time it happened, when YT introduced full HTML5 mode, there was a bug that for firefox, and only for firefox youtube was serving video with incompatible codec, the same as for Chrome, but Ff didn&#x27;t have that codec implemented yet, so video didn&#x27;t work. Opera was served video same as before, I noticed on reddit and other forums people were complaining on Firefox, that it stopped working on youtube. People started posting &quot;I&#x27;m moving to chrome because it works&quot;. I think it&#x27;s a plan to annoy firefox users by serving them not compatible videos so people move to Chrome. Google IS internet.