ViolentMonkey script
// ==UserScript== // @name Allow full screen on embedded Youtube // @namespace [email protected] // @homepage https://github.com/mwisnicki/userscripts/blob/master/allowfullscreen-youtube-embed.user.js // @match *://*/* // @grant none // @version 6 // @author [email protected] // @description ViolentMonkey script // ==/UserScript== const URLs = [ "https://www.youtube.com/embed/", "https://youtube.com/embed/", "https://www.youtube-nocookie.com/embed/" ]; const SELECTOR = URLs.map(url => `iframe[src^="${url}"]:not([allowfullscreen])`).join(', '); function reloadIframe(iframe) { iframe.src = iframe.src; } function fixVideos() { const iframes = document.body.querySelectorAll(SELECTOR) for (const iframe of iframes) { iframe.setAttribute("allowfullscreen",""); reloadIframe(iframe); console.log("Forced Youtube allowfullscreen on %o", iframe); } } fixVideos(); new MutationObserver(fixVideos).observe(document, { childList: true, subtree: true });