How to speed up HTML5 videos
Some video streaming websites like YouTube provides an option for speeding up/slowing down videos; some don’t. The trick is simple, find out the Video object via
and then set its playbackRate property to the desired value
document.querySelector("video").playbackRate = 2.0; // For 2X speed-up
These changes have to be made in the Developer console in Chrome or Browser console in Firefox.