Stop YouTube Play on Load

stop-youtube-play-on-load.js

(() => {
  let isVideoHandled = false; // Flag to indicate if the video has been handled

  const checkVideoStart = () => {
    const video = document.querySelector('#movie_player > div.html5-video-container > video');
    if (!video) return;

    // When the video starts playing (currentTime changes from 0), pause it
    if (video.currentTime > 0 && !video.paused) {
      video.pause();
      isVideoHandled = true;
      clearInterval(checkInterval); // Clear the interval after handling the video
    }
  };

  // Interval to periodically check if the video has started
  const checkInterval = setInterval(checkVideoStart, 100);

  // Cleanup function to clear the interval when the window is closed or navigated away
  const cleanup = () => {
    clearInterval(checkInterval);
    window.removeEventListener('beforeunload', cleanup);
  };

  window.addEventListener('beforeunload', cleanup);
})();

Fixed it to be more reliable.