A tool that tells you what leaks about your connection has no business collecting it. Concretely:
- No database. This site has no datastore attached. There is nowhere for a result to be written.
- No cookies. None are set, for any purpose, including analytics.
- No client-side analytics. The only script on the page is the diagnostics code, which is inlined and readable in view-source.
- No third-party requests except the ones you can see. The tests deliberately query public STUN and DNS-over-HTTPS providers, because that is what the tests are. Those providers see the request; that is unavoidable and is the point of the measurement.
- Browser-side results stay in the browser. WebRTC candidates, fingerprint surface, locale and latency results are computed locally and never posted back.
Cloudflare, as the platform this runs on, processes requests to serve them. Their handling is governed by their own terms.
Links to VPN providers may be affiliate links. That has no influence on the data shown, which is why several fields are blank rather than filled with a vendor's own marketing figure.