YouTube Ultrawide Fullscreen Bookmarklet

bookmarklet.js

// Bookmarklet will fullscreen the video and fill the screen
// Might not work on Chromium derivatives, probably same issue: https://github.com/dvlden/ultrawideo/issues/94

// One line
javascript:(function(){var e=document.querySelector(".ytp-fullscreen-button");if(e){e.click();setTimeout(function(){var e=document.querySelector("video");if(e){e.style.width="100vw",e.style.height="100vh",e.style.left="0px",e.style.top="0px"}},250)}})();

//Pretty + Comments
javascript:(function(){
  // Find the fullscreen button element
  var fullscreenButton = document.querySelector(".ytp-fullscreen-button");

  // If the button exists, click it and wait 250ms
  if (fullscreenButton) {
    fullscreenButton.click();
    setTimeout(function(){
      // Find the video element
      var video = document.querySelector("video");

      // If the video element exists, make it fullscreen
      if (video) {
        video.style.width = "100vw";
        video.style.height = "100vh";
        video.style.left = "0px";
        video.style.top = "0px";
      }
    }, 250);
  }
})();