A simple bookmarklet that displays the current URL with and without JavaScript side by side in the current window.
To install the bookmarklet either:
javascript:!function(){var e=document.createElement("style");e.innerHTML="\n .side-by-side{\n position:absolute;\n top:0;\n width: 50vw;\n height:100vh!important;\n z-index:999;\n }\n .side-by-side-nojs {\n left:50%;\n }\n .side-by-side-js {\n left:0;\n }\n .side-by-side-label {\n padding: 10px;\n background-color: black;\n color: white;\n font-size: 12px;\n position: absolute;\n z-index: 1000;\n margin: 10px;\n opacity: 0.7;\n text-transform: uppercase;\n font-family: 'Arial';\n pointer-events: none;\n }\n .no_js{\n left:50vw;\n }\n body{\n display:none!important;\n overflow:hidden!important;\n }\n ",document.head.appendChild(e);var n=document.createElement("div");n.setAttribute("class","js side-by-side-label"),n.innerText="JavaScript Enabled",document.body.insertAdjacentElement("afterend",n);var t=document.createElement("div");t.setAttribute("class","no_js side-by-side-label"),t.innerText="JavaScript Disabled",document.body.insertAdjacentElement("afterend",t);var i=document.createElement("iframe");i.setAttribute("class","side-by-side-nojs side-by-side"),i.src=window.location.href,i.frameBorder=0,i.sandbox="allow-forms allow-pointer-lock allow-popups allow-same-origin allow-top-navigation",document.body.insertAdjacentElement("afterend",i);var o=document.createElement("iframe");o.setAttribute("class","side-by-side-js side-by-side"),o.src=window.location.href,o.frameBorder=0,document.body.insertAdjacentElement("afterend",o)}();
Sites with X-Frame-Options: deny header will not work with this bookmarklet.
Questions? Contact me on Twitter @defaced