Redirect watch to embed

script.js

// ==UserScript==
// @name         Redirect watch to embed
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Redirect watch url to embed url.
// @author       karakufire
// @match        https://www.youtube.com/watch?v=*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// ==/UserScript==

(function() {
    'use strict';
    const videoID = document.location.toString().match(/(?:https?:\/\/www\.youtube\.com\/watch\?).*((?<=&?v=)[\w-]+).*/)[1];
    document.location.replace(`https://www.youtube.com/embed/${videoID}`);
})();