Greasy Fork

// ==UserScript==// @name            Get YouTube Thumbnail// @version         0.9// @description     Adds button to view largest thumbnail image for any video// @author          Drazen Bjelovuk// @match           *://www.youtube.com/*// @grant           none// @run-at          document-end// @namespace       https://gfork.dahi.icu/users/11679// @contributionURL https://goo.gl/dYIygm// ==/UserScript==document.addEventListener('spfdone', addThumbnailButton);document.addEventListener('yt-navigate-start', addThumbnailButton);addThumbnailButton();const sizes = ['/maxresdefault.jpg', '/hqdefault.jpg', '/mqdefault.jpg', '/sddefault.jpg'];var vidId;function tryLoad(index) {var image = new Image();image.onload = function(img) {if (img.path[0].naturalWidth > 120) {spinner.querySelector('#spinnerContainer').classList.remove('active');window.open(img.path[0].src);}else if (index < sizes.length - 1) {tryLoad(index + 1);}};image.src = 'https://img.youtube.com/vi/'+ vidId + sizes[index];}var interval;var spinnerTemplate = document.createElement('template');spinnerTemplate.innerHTML = '<paper-spinner id="thumbnailSpinner" class="style-scope yt-next-continuation"><div id="spinnerContainer" class="style-scope paper-spinner"><div class="spinner-layer layer-1 style-scope paper-spinner"><div class="circle-clipper left style-scope paper-spinner"></div><div class="circle-clipper right style-scope paper-spinner"></div></div><div class="spinner-layer layer-2 style-scope paper-spinner"><div class="circle-clipper left style-scope paper-spinner"></div><div class="circle-clipper right style-scope paper-spinner"></div></div><div class="spinner-layer layer-3 style-scope paper-spinner"><div class="circle-clipper left style-scope paper-spinner"></div><div class="circle-clipper right style-scope paper-spinner"></div></div><div class="spinner-layer layer-4 style-scope paper-spinner"><div class="circle-clipper left style-scope paper-spinner"></div><div class="circle-clipper right style-scope paper-spinner"></div></div></div></paper-spinner>';var spinner = spinnerTemplate.content.firstChild;function addThumbnailButton() {var button = document.getElementById('viewThumbnailBtn');if (button) button.remove();var subscribeButton = document.querySelector('ytd-video-secondary-info-renderer #subscribe-button');if (subscribeButton) {button = document.createElement('tp-yt-paper-button');button.id = 'viewThumbnailBtn';button.className = 'style-scope ytd-subscribe-button-renderer';button.style.cssText = 'margin-left: 10px';button.textContent = 'View Thumbnail';button.onclick = function() {spinner.querySelector('#spinnerContainer').classList.add('active');vidId = document.querySelector('[video-id]').getAttribute('video-id');tryLoad(0);};subscribeButton.parentNode.insertBefore(button, subscribeButton);subscribeButton.parentNode.insertBefore(spinner, button);clearInterval(interval);}else if (~window.location.href.indexOf('v=')) {clearInterval(interval);interval = setInterval(addThumbnailButton, 500);}}