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YouTube Autoplay Fix

Fixes YouTube autoplay not working for playlists past 400 entries

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         YouTube Autoplay Fix
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @namespace    https://github.com/Sikarii/Userscripts
// @description  Fixes YouTube autoplay not working for playlists past 400 entries
// @version      1.0.2
// @match        https://www.youtube.com/watch*&list=*
// @grant        none
// ==/UserScript==

const hookPlayer = () => {
  const playerEl = document.querySelector("video.html5-main-video");
  if (!playerEl) {
    return;
  }

  playerEl.addEventListener("ended", () => {
    playerEl.paused && setTimeout(switchToNextVideo, 2000);
  });
};

const switchToNextVideo = () => {
  const panelEls = [
    ...document.querySelectorAll("ytd-playlist-panel-video-renderer"),
  ];

  const selectedIdx = panelEls.findIndex((x) => x.hasAttribute("selected"));

  const nextElement = panelEls[selectedIdx + 1];
  if (!nextElement) {
    return;
  }

  const thumbnailEl = nextElement.querySelector("#thumbnail");
  return thumbnailEl?.click();
};

(function () {
  "use strict";

  const params = new URLSearchParams(window.location.search);

  const inPlaylist = params.has("list");
  const playlistIndex = parseInt(params.get("index"));

  // Playlists break past 400 videos, so we better fix it
  return inPlaylist && playlistIndex >= 400 && hookPlayer();
})();