Download websites that use Understrap

About Understrap

A starter theme is not something a site owner buys. Understrap is a PHP codebase that a developer clones at the start of a build and then edits, so finding it on a site says more about who made the site than about what the site sells. The fingerprint survives the editing because most builds keep the theme directory and the stylesheet header intact even after the templates inside have been rewritten.

The inheritance cuts both ways. A match confirms that someone began from the boilerplate, but it says nothing about how much of the original code remains, and a heavily customised child theme can look nothing like the reference build. A hit is evidence of an origin rather than of a current design, and any analysis built on it should be framed that way.

Availability under a GPL v2 licence since 2015 is part of the commercial story rather than a footnote. Free redistribution is what let the theme spread through agencies and freelancers who needed a defensible starting point for client work instead of a licence they would have to explain to the client. The result is a population of sites that look bespoke on the surface and are conventional underneath, which is a combination worth being able to isolate.

As of October 2026 we detect Understrap on 3,277 sites. The figure is modest next to the platform the theme extends, and the modesty is the point. Filtering a vast content management population down to sites built on a developer boilerplate isolates a segment that behaves unlike sites assembled from a template gallery. Boilerplate sites usually have an agency or a contractor attached, a budget that paid for custom work, and no theme vendor sitting in the middle of the relationship.

Two audiences ask for the list, from opposite ends. Companies selling into the professional build market want sites that had money spent on them, because those owners have already demonstrated a willingness to pay for work. Maintenance and security vendors want the same sites for the opposite reason: a boilerplate is frozen at the release it was cloned from, receives none of the updates a distributed theme would push out, and has nobody upstream responsible for it.

A per-domain lookup cannot serve either use, because both start from the set of sites rather than from a domain already in hand. Detection also has a floor worth stating. Builds that rename the theme directory or compile the stylesheet header away will not match, so the count should be read as a lower bound rather than a census.