Download websites that use VWO

About VWO

An A/B testing tag is a revealing thing to find in a page's source, because nobody installs one by accident. VWO belongs to the A/B Testing category, and its presence says that somebody at the organisation has a hypothesis about the site, a budget to test it, and usually a person whose job title mentions conversion. Brochure sites do not carry experimentation code. Sites that are measured against revenue do.

VWO was built by Wingify and released in 2009, in the wave of hosted optimisation tools that moved experimentation out of engineering and into marketing. The product is Proprietary and delivered as a JavaScript snippet loaded into the page, covering split URL tests, multivariate tests, heatmaps, session recordings and funnel reports. The commercial consequence of a snippet architecture matters more than the feature list. A marketing team can adopt the tool without a deploy, and can leave it in place long after the experiment that justified it has finished.

The last point is also the honest caveat on any list built from tag detection. We can see that the script is served on a page we crawled. We cannot see whether an experiment is currently running, how much traffic it receives, or which plan the account sits on. A dormant tag and an active testing programme look identical from the outside, so the list is evidence of adoption rather than evidence of activity.

Within that limit the population is a useful one. As of September 2026 we detect VWO on 3,414 sites, and having all of them in a single file changes the shape of the question you can ask. A per-domain lookup answers whether a company you already named runs the tool. A downloadable list answers questions you cannot phrase as a domain: which sectors carry testing budgets, how experimentation tooling clusters by platform and by market, which customers of a competing product sit alongside one another, and how the base moves between refreshes.

The people asking those questions are usually selling something adjacent. Vendors of analytics, personalisation, feature flagging and conversion consultancy treat an installed testing tag as a qualification signal, because the buyer has already accepted that the category is worth paying for. Agencies use it in reverse, to find sites that are optimising and pitch the work. Researchers use it to size the experimentation market without relying on vendor claims. Every one of those uses needs the whole set, joined to the rest of a site's stack, rather than a single answer at a time.