YouTube appears to require Flash when playing a video with ads from the YouTube site. Embeds of the same video show the HTML5 version ad-free.
Here's a tip I've found useful: if you run into the "Install Flash" message, you can usually edit the URL to play in HTML5 instead. Change "watch?v=" to "embed/" (and if there are other querystring arguments starting with an ampersand, just strip them off). There are a few YouTube gateway sites that do something similar, but I remember the 'embed' trick better.
Re:HTML5 Video in Safari on OS X Yosemite
by stevoyoung on Tuesday June 03, 2014 @02:33PM
(#7841967)
I use the "click to flash" plugin on Safari to block flash. On YouTube, the html 5 video version loads 100% of the time for me. I also have no problem with playing them full screen.
Am I missing something or do I just not watch enough YouTube to come across the problem you are describing?
This has nothing to do with browser technology though correct? This is just individual sites not being more proactive about providing desktop fallbacks.
If you want a short term solution, I usually just swap to an iPad user agent string if I want to force html5 video.
At the moment I get the "install flash" message on Youtube videos a disappointingly often amount of the time. Weirdly I've had the experience where embedded HTML5 Youtube videos will play, but they won't when I click through to watch the full-size video on Youtube.