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Analytics

Websites Using VWO

VWO (Visual Website Optimizer) is an A/B testing, heatmap and conversion-optimization suite aimed at marketing and growth teams.

The source-code fingerprint

The account library loads from dev.visualwebsiteoptimizer.com/j.php, so that host appears in a script tag alongside the account ID; the inline _vwo_code snippet is an alternative marker.

Likely false positives: The async loader is often present with no campaign running; read a match as 'VWO installed', not 'test active'.

Example websites using VWO

These domains all contain the dev.visualwebsiteoptimizer.com fingerprint in their homepage source right now. A match is a verified substring of the live page, so confidence is high, the false positives noted above are the main caveat.

• www.forbes.com ...r n = this.getCombinationCookie();\n\t\t\t\t\t\tthis.load('https://dev.visualwebsiteoptimizer.com/j.php?a=' + account_id + '&u=' + encodeURIComponent(d.URL) ...
• www.weforum.org ...ld(d.createTextNode(b));h.appendChild(a);this.load('https://dev.visualwebsiteoptimizer.com/j.php?a='+account_id+'&u='+encodeURIComponent(d.URL)+'&f='+...
• www.ted.com ...s/gpt.js" as="script"/><link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com"/><link rel="preconnect" href="https://sli.ted.com" crossor...
• www.uber.com ...om eu.srv.stackadapt.com https://bzr.openai.com/v1/ https://dev.visualwebsiteoptimizer.com/j.php https://accounts.google.com https://auth.uber.com htt...
• foursquare.com ...O Async SmartCode -->\r\n<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\r\n<script type='text/plain' id='vwoCode' class="optanon-...
• searchengineland.com ... Async SmartCode -->\n\t\t<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n\t\t<script type='text/javascript' id='vwoCode'>\n\t\twindow...
• www.oecd.org ...ensearch.xml"/>\n\n\n\n <link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com/"/>\n <script type='text/javascript' id='vwoCode'>\n\n ...
• www.merriam-webster.com ...WO Async SmartCode -->\n<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n<script type='text/javascript' id='vwoCode'>\nwindow._vw...
• www.upwork.com .../"><link data-n-head="ssr" rel="dns-prefetch" href="https://dev.visualwebsiteoptimizer.com/"><script data-n-head="ssr" type="application/ld+json">{"@c...
• www.constantcontact.com ...images.ctfassets.net"/><link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com"/><link rel="preconnect" href="https://logx.optimizely.com"...
• www.britannica.com ...</script>\n\n\n\n \n\n <link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n<script type='text/javascript' id='vwoCode'>\n window...
• www.qualtrics.com ...c V3.0 SmartCode -->\n <link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n <script type="text/javascript" id="vwoCode">\n window...
• www.oreilly.com ...O Async SmartCode -->\r\n<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\r\n<script type='text/javascript' id='vwoCode'>\r\nwindow._...
• www.checkpoint.com ... Async SmartCode -->\n <link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" class="optanon-category-C0002" />\n <script type='text/jav...
• www.taboola.com ...O Async SmartCode -->\n\t<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n\t<script type='text/javascript' id='vwoCode'>\n\t\twindow....
• www.cognitoforms.com ...VWO Async SmartCode --><link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com"><script type="text/javascript" id="vwoCode">\n\t\twindow._vwo...
• www.kobo.com ...licy="no-referrer-when-downgrade" id="vwoCode" src="https://dev.visualwebsiteoptimizer.com/lib/778105.js"></script><script src="/_next/static/chunks/p...
• teachable.com ...WO Async SmartCode -->\n<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n<script type='text/javascript' id='vwoCode'>\nwindow._vw...
• www.myfonts.com ...nc SmartCode -->\n <link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n <script type='text/javascript' id='vwoCode'>\n ...
• www.moma.org ...184};\n </script>\n\n \n\n<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n<script type='text/javascript' id='vwoCode'>\nwindow._vw...
• www.appsflyer.com ... var c=this.getCombinationCookie();this.load("https://dev.visualwebsiteoptimizer.com/j.php?a="+account_id+"&u="+encodeURIComponent(d.URL)+"&f="+...
• www.backblaze.com ...for backblaze.com -->\n\n<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n<script>\n function vwo() {\n window._vwo_code || (fu...
• www.techopedia.com ...O Async SmartCode -->\n\t<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n\t<script data-cfasync="false" nowprocket type='text/jav...
• www.aweber.com ...WO Async SmartCode -->\n<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com">\n<script type="text/javascript" id="vwoCode">\nwindow._vwo_...
• convertkit.com ...ild(e);var n=this.getCombinationCookie();this.load('https://dev.visualwebsiteoptimizer.com/j.php?a='+account_id+'&u='+encodeURIComponent(d.URL)+'&f='+...
• www.webfx.com ...nc SmartCode -->\n <link rel="dns-prefetch" href="https://dev.visualwebsiteoptimizer.com" />\n <script type="text/javascript" id="vwoCode">\n wi...
• www.business2community.com ...O Async SmartCode -->\n\t<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n\t<script data-cfasync="false" nowprocket type='text/jav...
• wp-rocket.me ...WO Async SmartCode -->\n<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com"/>\n<!-- IMPORTANT: data-cfasync="false" must be preserved o...
• www.dashlane.com ...th" data-next-head=""/><link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com"/><style type="text/css">@font-face {font-family:'Public Sa...
• www.wordstream.com ...O Async SmartCode -->\n\t<link rel="preconnect" href="https://dev.visualwebsiteoptimizer.com" />\n\t<script type='text/javascript' id='vwoCode'>\n\twindow._...

Showing 30 of 54,187 matching sites. Open the full ranked list, inspect the matched source, and export the domain list →

Related technologies

How this works

SearchWebCode indexes the raw HTML, CSS and JavaScript source of public web pages. To find sites using VWO we match the literal fingerprint dev.visualwebsiteoptimizer.com, the code VWO ships, against that index, then verify each match against the raw source. Counts reflect the current index (129,313,463 domains, refreshed monthly, last built August 2026) and grow as we scale toward the whole web. Run the search yourself to see every match, view the full page source for any result, filter by TLD or regex, and export the domain list.

Comparing adoption across tools? The Web Technology Adoption Report ranks the most common tags in the index side by side.