automatically remove YT video from Watch Later

content.js

let videoMonitor = null;
let currentVideoId = null;
let autoRemovalTriggered = false;

function getCurrentVideoId() {
  const location = new URL(window.location.href);
  let videoId = location.searchParams.get("v");
  
  if (location.pathname.startsWith("/shorts/")) {
    videoId = location.pathname.split("/")[2];
  }
  
  return videoId;
}

function removeFromWatchLater(videoId) {
  const getRemoveVideoParams = (videoId) => ({
    clickTrackingParams: "",
    commandMetadata: { webCommandMetadata: { sendPost: true, apiUrl: "/youtubei/v1/browse/edit_playlist" } },
    playlistEditEndpoint: { playlistId: "WL", actions: [{ action: "ACTION_REMOVE_VIDEO_BY_VIDEO_ID", removedVideoId: videoId }] }
  });

  const appElement = document.querySelector("ytd-app");
  if (!appElement) return;

  const event = new window.CustomEvent('yt-action', {
    detail: {
      actionName: 'yt-service-request',
      returnValue: [],
      args: [{ data: {} }, getRemoveVideoParams(videoId)],
      optionalAction: false,
    }
  });

  appElement.dispatchEvent(event);
  console.log('Auto-removed video from Watch Later:', videoId);
}

function monitorVideoProgress() {
  const video = document.querySelector('video');
  if (!video) return;

  const checkProgress = () => {
    if (video.duration && video.currentTime) {
      const remainingTime = video.duration - video.currentTime;
      // 95% reached, or remaining 60s
      const triggerThreshold = Math.max(video.duration * 0.05, 60);
      
      if (remainingTime <= triggerThreshold && remainingTime > 0 && !autoRemovalTriggered) {
        const videoId = getCurrentVideoId();
        if (videoId) {
          autoRemovalTriggered = true;
          removeFromWatchLater(videoId);
        }
      }
    }
  };

  video.addEventListener('timeupdate', checkProgress);
  
  return () => {
    video.removeEventListener('timeupdate', checkProgress);
  };
}

function startMonitoring() {
  const videoId = getCurrentVideoId();
  
  if (videoId !== currentVideoId) {
    currentVideoId = videoId;
    autoRemovalTriggered = false;
    
    if (videoMonitor) {
      videoMonitor();
    }
    
    const waitForVideo = () => {
      const video = document.querySelector('video');
      if (video) {
        videoMonitor = monitorVideoProgress();
      } else {
        setTimeout(waitForVideo, 1000);
      }
    };
    
    waitForVideo();
  }
}

function handleNavigation() {
  startMonitoring();
}

const observer = new MutationObserver((mutations) => {
  mutations.forEach((mutation) => {
    if (mutation.type === 'childList') {
      const addedNodes = Array.from(mutation.addedNodes);
      if (addedNodes.some(node => 
        node.nodeType === Node.ELEMENT_NODE && 
        (node.matches('ytd-watch-flexy') || node.querySelector('ytd-watch-flexy'))
      )) {
        setTimeout(handleNavigation, 1000);
      }
    }
  });
});

observer.observe(document.body, {
  childList: true,
  subtree: true
});

window.addEventListener('yt-navigate-finish', handleNavigation);
window.addEventListener('popstate', handleNavigation);

setTimeout(startMonitoring, 2000);

manifest.json

{
  "manifest_version": 3,
  "name": "YouTube Auto Watch Later",
  "version": "1.0",
  "description": "Automatically manage YouTube Watch Later playlist",
  "permissions": [
    "scripting",
    "tabs",
    "activeTab"
  ],
  "host_permissions": [
    "https://www.youtube.com/*"
  ],
  "content_scripts": [
    {
      "matches": ["https://www.youtube.com/*"],
      "js": ["content.js"],
      "run_at": "document_idle"
    }
  ]
}