set speed for html video element code example
Example 1: how to set video speed html
/* play video twice as fast */
document.querySelector('video').defaultPlaybackRate = 2.0;
document.querySelector('video').play();
/* now play three times as fast just for the heck of it */
document.querySelector('video').playbackRate = 3.0;
Example 2: increase video speed html5
document.querySelector('video').playbackRate = 1.25;