Download websites that use K2

About K2

Extensions are usually invisible in technology data, which is what makes K2 worth a page of its own. The software is not a content management system. The software is a content construction kit that sits on top of Joomla, adding structured content types, custom fields, tags, user profiles, comments and access control that the host platform did not originally provide. A site running it is a Joomla site, but a particular kind of Joomla site.

JoomlaWorks released the extension in 2008, written in PHP and distributed under the GPL v2 licence, at a moment when Joomla's own content model was thin and anybody building a news portal, a directory, a magazine or a member community had to extend it or leave. Editorial teams adopted it, built their templates around its item structure, and then stayed, because content modelled inside an extension does not move to a new platform without being rebuilt.

Lock in of that kind is the real story in the detection. A site carrying K2 holds years of articles, images and taxonomies in a schema owned by a third party extension rather than by the core Miscellaneous. Migration means remapping every field, so these sites tend to be old, content heavy and administered by people who know they are on borrowed time. News publishers, universities, regional government portals, associations and long running company sites are common in the population.

Several audiences read the same fact in opposite directions. Agencies selling replatforming work see accounts with a hard problem and a reason to pay for help. Competing content platforms see prospects whose switching cost is known and can be quantified. Security teams see a dependency that outlives the attention paid to it, since an extension is patched on its own schedule and updates far less reliably than the core it runs on. Hosting companies see a support burden they may want to price differently.

Detection is inferential and the caveat matters more here than usual, because an extension leaves fainter traces than a platform does. Recognition depends on markup, class names, asset paths and similar fragments that a customised template can remove entirely, and a site can use the extension only on a section we never fetch. As of October 2026 we detect it on 1,938 sites, a figure best read as a visible minimum rather than an installed base.

What the list adds is the ability to treat the population as a market. One lookup tells you that a single domain runs the extension. The export shows the whole set beside the server software, the analytics, the payment tooling and the country and top level domain distribution, which is how outreach gets prioritised, how a migration offer gets sized, and how the slow decline of an extension ecosystem can be measured instead of assumed.