Youtube videos have really bad frame rate?

[The Struggle]

This is honestly pretty confusing to me, because it is only youtube videos that do this. Any youtube video I watch fluctuates between 10-20 FPS.

and NO don't tell me it is my computer's fault because it isn't. i-3 intel proccessor 3.40 GHz and 8GB RAM.

Is this a known problem and is there a way to fix it?
because, i can play games on the computer at high settings and watch live streams and such perfectly fine
and no the video isnt shaky or stuttery or anything like that, it is just a really low fps
I found a soloution and like I said, NOTHING to do with my computer. I had to switch to HTML5...CYBER did have the best answer however even if it wasn't helpful