Userscript for adding download links to instagram videos on the instagram website.

download_instagram_videos.user.js

// ==UserScript==
// @name         Download Instagram Videos
// @namespace    https://www.instagram.com/
// @version      0.1
// @description  Adds download links for videos, even on private accounts.
// @author       Evan Straw
// @include     http://www.instagram.com/*
// @include     https://www.instagram.com/*
// @grant        none
// ==/UserScript==

(function() {
    setInterval(addDownloadLinks,100);
    setInterval(checkURLChange,100);
})();

function getVideoElements(root){
    if(root){
        return root.getElementsByTagName("video");
    }
    else{
        return document.getElementsByTagName("video");
    }
}

function getNumVideos(root){
    return getVideoElements(root).length;
}

function isPostPage(){
    return window.location.pathname.startsWith("/p/");
}

function makeDLLink(url){
    let linkElement = document.createElement("A");
    linkElement.href = url;
    linkElement.innerText = "Download Video";
    linkElement.target = "_blank";
    linkElement.style = "padding: 10px;font-size:1.5em;font-weight:bold;";
    linkElement.classList.add("download-link");
    return linkElement;
}

function alreadyHasLink(element){
    return element.getElementsByClassName("download-link").length > 0;
}

function getLink(element){
    return element.getElementsByClassName("download-link")[0];
}

function addDownloadLinks(){
    let articles = document.getElementsByTagName("article");
    for(let article of articles){
        if(getNumVideos(article)>0){
            let videos = getVideoElements(article);
            let dlLink = videos[0].src;
            if(alreadyHasLink(article)){
                let link = getLink(article);
                if(link.href!==dlLink){
                    link.parentElement.removeChild(link);
                    let linkElement = makeDLLink(dlLink);
                    article.append(linkElement);
                }
            }
            else{
                let linkElement = makeDLLink(dlLink);
                article.append(linkElement);
            }
        }
    }
}