Raw Source
distillvideo / The best Video & Audio Downloader from 5000+ sites including Youtube, Support 1080P, 2K, 4k, 6K & 8K 

// ==UserScript==
// @name        The best Video & Audio Downloader from 5000+ sites including Youtube, Support 1080P, 2K, 4k, 6K & 8K
// @namespace   https://distillvideo.com/
// @version     3.0
// @date        2018-06-23
// @description Download video and music (audio) from Youtube, Twitter, Vimeo, Facebook, Instagram, SoundCloud, Dailymotion, Liveleak, Break, Imgur, Mashable, 1tv, VK, TED, youku, bilibili and 5000 more sites for free. Also support to download subtitles. Free, fast and easy to use. No need to install any annoying softwares. Supporting MP4, WEBM, AVI, 3GP, MP3, M4A, 8K, 6K,4K, 2K, 1080, 720, 480 ,360, etc.
// @author      DistillVideo.com
// @copyright   2018, distillvideo (https://openuserjs.org/users/distillvideo)
// @homepage    https://distillvideo.com/extension#extension
// @downloadURL https://distillvideo.com/js/ditillvideo.user.js
// @license    MIT
// @include          *://*.youtube.com/*
// @grant none
// ==/UserScript==

(function() {
    'use strict';

    if (document.getElementById("polymer-app") || document.getElementById("masthead") || window.Polymer) {
    setInterval(function() {
        if (window.location.href.indexOf("watch?v=") < 0) {
            return false;
        }
        if (document.getElementById("count") && document.getElementById("distillvideo") === null) {
            Addytpolymer();
        }
    }, 100);
} else {
    setInterval(function() {
        if (window.location.href.indexOf("watch?v=") < 0) {
            return false;
        }
        if (document.getElementById("watch7-subscription-container") && document.getElementById("distillvideo") === null) {
            AddhtmlDV();
        }
    }, 100);
}

function AddhtmlDV() {
    if (document.getElementById("watch7-subscription-container")) {
        var wrap = document.getElementById('watch7-subscription-container');
        var button = "<div id='distillvideo' style='display: inline-block; margin-left: 10px; vertical-align: middle;'>";
        button += "<a href=\"https://distillvideo.com/?url=" + window.location.href + "\" title=\"Download this video\" target=\"_blank\"" +
            "style=\"display: inline-block; font-size: inherit; height: 22px; border: 1px solid rgb(0, 183, 90); border-radius: 3px; padding-left: 28px; cursor: pointer; vertical-align: middle; position: relative; line-height: 22px; text-decoration: none; z-index: 1; color: rgb(255, 255, 255);\">";
        button += "<i style=\"position: absolute; display: inline-block; left: 6px; top: 3px; background-image: url(data:image/svg+xml;base64,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); background-size: 12px; background-repeat: no-repeat; background-position: center center; width: 16px; height: 16px;\"></i>";
        button += "<span style=\"padding-right: 12px;\">Download</span></a></div>";
        var style = "<style>#distillvideo button::-moz-focus-inner{padding:0;margin:0}#distillvideo a{background-color:#15388c}#distillvideo a:hover{background-color:#E91E63}#distillvideo a:active{background-color:rgb(0, 151, 74)}</style>";
        var tmp = wrap.innerHTML;
        wrap.innerHTML = tmp + button + style;
    }
}

function Addytpolymer() {
    var buttonDiv = document.createElement("span");
    buttonDiv.style.width = "100%";
    buttonDiv.id = "distillvideo";
    var addButton = document.createElement("a");
    addButton.appendChild(document.createTextNode("Download Video"));
    addButton.style.width = "100%";
    addButton.style.backgroundColor = "#15388c";
    addButton.style.color = "white";
    addButton.style.textAlign = "center";
    addButton.style.padding = "5px 10px";
    addButton.style.margin = "0px 10px";
    addButton.style.fontSize = "14px";
    addButton.style.border = "0";
    addButton.style.cursor = "pointer";
    addButton.style.borderRadius = "2px";
    addButton.style.fontFamily = "Roboto, Arial, sans-serif";
    addButton.style.textDecoration = "none";
    addButton.href = "https://distillvideo.com/?url=" + window.location.href;
    addButton.target = "_blank";
    buttonDiv.appendChild(addButton);
    var targetElement = document.querySelectorAll("[id='count']");
    for (var i = 0; i < targetElement.length; i++) {
        if (targetElement[i].className.indexOf("ytd-video-primary-info-renderer") > -1) {
            targetElement[i].appendChild(buttonDiv);
        }
    }
}


})();