JavaScript code to change the speed videos on the internet using "[" and "]".

changeSpeed.js

const getAllVideos = () => Array.from(document.getElementsByTagName("video"));

const changeSpeedAllVideos = ({ to }) => {
  to = Math.min(Math.max(to, 0.5), 6);
  getAllVideos().forEach((video) => (video.playbackRate = to));
  console.log("new playback speed is " + to.toFixed(2));
};

const changeSpeedSlightly = ({ key }) => {
  const videos = getAllVideos();
  const currentSpeed = videos[0].playbackRate;
  if (key === "[") changeSpeedAllVideos({ to: currentSpeed - 0.15 });
  if (key === "]") changeSpeedAllVideos({ to: currentSpeed + 0.15 });
};

getAllVideos().forEach((video) => (video.playbackRate = 1));
document.body.addEventListener("keypress", changeSpeedSlightly);