Which extensions is your browser
telling every website about?
Chrome extensions leak signals that any page can read. This one reads them back to you — a live fingerprint of what you have installed, built the moment you loaded this page.
🔒 Nothing leaves your browser. There is no server, no analytics, no request off this machine — every check runs locally in the page you're reading. Open devtools and watch.
How a website can see your extensions
Most extensions ship files any page is allowed to load. A request for
chrome-extension://<id>/icon.png that succeeds is proof —
the ID is right there in the URL, and the file only loads if the extension is
installed. One request, no ambiguity.
Others give nothing away directly, but change the page — a writing assistant tags an editable box, a password manager reacts to a login form, a dark-mode extension rewrites your colours. Each leaves a vendor-named mark that names the extension behind it.
What can't be seen
Across the 500 most-installed extensions, 328 are identifiable and 172 resist — and which side an extension lands on is decided by how it's built, not by how popular it is. The ones that hide do it in a handful of structural ways:
The full per-extension writeups — including why the big ad blockers can't be uniquely identified even by baiting them with fake ads — are in the repository.