Tiny script to change currently playing HTML video speed

changePlaybackRate.js

// Copy & Paste to the browser's console and call function to adjust playbackRate for currenly playing videos
// Common playback rates are 0.25 / 0.5 / 0.75 / 1.0 / 1.25 / 1.5 / 1.75 / 2.0
// Maximum value recommended is 4.0 (browser / hardward dependent)
// @param {Number} [rate = 1.0]

function changePlaybackRate(rate) {
  var videos = document.getElementsByTagName('video');
  var currentlyPlaying = [];
  var playbackRate = Number(rate) || 1.0;
  for (var i = 0; i < videos.length; i++) {
    if (!videos[i].paused) {
      currentlyPlaying.push(videos[i]);
    }
  }
  currentlyPlaying[0].playbackRate = playbackRate;
}