What this tool checks
WordPress often leaves several public clues about its presence and version: a <meta name="generator"> tag in every page's source, a readme.html file that spells out the version in plain text, and a recognizable file structure (/wp-content/, /wp-includes/). This tool checks all three signals and folds the results into a single verdict.
Why the version matters
WordPress ships security fixes on a regular cadence, and every vulnerability disclosure names the versions affected. A site still running a version that's months old probably hasn't picked up the latest patches — that's not proof of a vulnerability by itself, but it's the first thing anyone scanning the web for easy targets looks for. Knowing your own exposed version lets you check whether you're current before someone else notices you're not.
Why some sites aren't detected as WordPress
Hiding the generator tag and deleting readme.html are standard WordPress hardening recommendations — plenty of security guides tell you to do both. A properly hardened site that's done so won't return a version here, and this tool falls back to checking for characteristic paths (/wp-content/, /wp-includes/, /wp-login.php) to at least confirm WordPress is running, even without a version number.
What this detector doesn't do
It doesn't try to identify installed plugins or themes — that kind of detection relies on static file fingerprints that are unreliable, with a high error rate and constant upkeep as things change. This detector sticks to WordPress core, the one part where detection stays reliable over time.
A concrete example
A site displaying WordPress 5.2 in its generator tag, when the current release is far ahead of that, deserves an immediate look: every intervening major version has patched known vulnerabilities that could still be exploitable there. On the other hand, a site that reveals no version number but still answers correctly at /wp-content/ is simply a well-configured WordPress install — cautious about publishing information, not a red flag on its own.