YouTube - Hide chat by default

Hide chat on YouTube live videos by default.

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 or Violentmonkey 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 - Hide chat by default
// @namespace    amekusa.yt-hide-chat
// @author       amekusa
// @version      2.0.0
// @description  Hide chat on YouTube live videos by default.
// @match        https://www.youtube.com/*
// @run-at       document-start
// @grant        none
// @license      MIT
// @homepage     https://github.com/amekusa/monkeyscripts
// ==/UserScript==

(function (doc) {
	// --- config ---
	let wait     = 4000; // initial wait time (ms)
	let interval = 2000; // update interval (ms)
	let match    = /^https:\/\/www\.youtube\.com\/(?:watch\?|clip\/)/; // url pattern
	let debug    = false ? console.debug : (() => {});
	// --------------

	let watcher;
	let paused;
	let hide;

	function findCloseButton() {
		try {
			let fr = doc.querySelector('iframe#chatframe'); // frame
			if (!fr) return null;
			fr = fr.contentWindow.document;
			if (!fr.querySelector('yt-live-chat-item-list-renderer #items [id], yt-live-chat-item-list-renderer #empty-state-message')) return null;
			return fr.querySelector('yt-live-chat-header-renderer #close-button button');
		} catch (e) {
			return null;
		}
	}

	function unhide() {
		debug('unhide.');
		hide = false;
	}

	function update() {
		if (paused || !hide) return; // do nothing

		// find & click the close button
		let btn = findCloseButton();
		if (btn) {
			debug('click:', btn);
			return btn.dispatchEvent(new Event('click'));
		}

		// hook "Show chat" button
		btn = doc.querySelector('#chat-container #show-hide-button button');
		if (btn) {
			btn.removeEventListener('click', unhide);
			btn.addEventListener('click', unhide);
		}
	}

	function pause() {
		if (paused) return;
		debug('pause.');
		paused = true;
		if (watcher) {
			clearTimeout(watcher);
			clearInterval(watcher);
			watcher = null;
		}
	}

	function init() {
		if (watcher) return; // already running
		if (!location.href.match(match)) {
			debug('url mismatch:', location.href);
			return;
		}
		if (paused) {
			debug('resume.');
			paused = false;
		}
		debug('initializing...');
		hide = true;
		watcher = setTimeout(() => {
			watcher = setInterval(update, interval);
			debug('initialized.');
			update();
		}, wait);
	}

	doc.addEventListener('DOMContentLoaded', init);
	doc.addEventListener('yt-navigate-finish', init);
	doc.addEventListener('yt-navigate-start', pause);

})(document);