Download websites that use Solr

About Solr

Finding a search server from the open internet is usually somebody's mistake. Solr is meant to sit on a private network behind an application, and yet the fingerprints that identify it are exactly the kind a public site emits when configuration drifts: an admin interface left reachable, a query endpoint proxied straight through to the browser, parameters in a URL that only one class of search server uses, a response header nobody trimmed.

So a detection here carries a double meaning, and the pair is worth separating before the data gets used. In one reading, the domain runs self managed search infrastructure: an index it controls, a schema somebody tuned, a Java service to keep alive. In the other, the domain has an exposure, because a query endpoint reachable from outside is an information disclosure at best. Each reading comes from the same row, and only a manual look at the domain tells them apart.

The provenance is unusually clean for an entry of this kind. Solr is maintained by Apache Software Foundation under Apache 2.0 and dates to 2006, which leaves no acquisition history to untangle and no licensing to argue about. Nobody pays to run it, so presence says nothing about budget directly. What presence does say is that the organisation chose to operate search rather than rent it, and operating search is a staffing decision: someone knows Java, someone owns the index, someone gets paged when relevance breaks.

There is a scale implication as well. A site that puts a dedicated search server in front of a catalogue is telling you something about volume, because teams reach for one when the database query stopped being enough: large product sets, document archives, multilingual corpora, faceted browsing a generic plugin cannot deliver. Domains in this entry skew towards organisations with a lot of content and a reason to make it findable, which is a more specific audience than a shop or content system fingerprint gives you.

Age matters for the security reading. A server product dating to 2006 has accumulated a long advisory history, and self hosted infrastructure upgrades on nobody's schedule but its owner's. We carry no version breakdown for this entry, so the rows cannot tell you which installations are current. What the rows can tell you is where to look, which is the part nobody reconstructs by checking domains one at a time.

As of October 2026 we record Solr on 12 sites, and the figure should be read as a visibility count rather than an install base. Every properly firewalled deployment is invisible to us by design, and the well run installations are precisely the ones missing from the list. For a hosted search vendor sizing the self managed market, for a consultancy selling migrations, or for a researcher measuring how much infrastructure sits accidentally exposed, an inventory of the visible ones is still the only starting point on offer.