I'm late to respond to this, but this is really not true (speaking as a several-year (and current) user of click to play Flash). I would suggest checking the h

I'm late to respond to this, but this is really not true (speaking as a several-year (and current) user of click to play Flash). I would suggest checking the https://www.youtube.com/html5 https://www.youtube.com/html5 page sp332 suggested to see if you have checks in all those boxes and making sure you're using a recent version of whatever browser you're running[1]. Only if your browser doesn't support the needed html5 video features does it switch back to flash. [1] https://bugzilla.mozilla.org/show_bug.cgi?id=778617 https://bugzilla.mozilla.org/show_bug.cgi?id=778617 for the ongoing Firefox bug, but you should be good with MSE in recent Firefox on Youtube in particular (see last comment in that bug)