What this page does and does not measure
Browser JavaScript cannot issue a raw DNS query. That is not a limitation of this tool; it is a property of the web platform. Any page claiming to have inspected the resolver your operating system uses on port 53 is overstating what it did.
What these checks can establish is whether the answers arriving through encrypted resolvers match values that are fixed worldwide. Where they do not, an answer was substituted somewhere on the path — and that is a real finding, not an inference.
The one test that identifies your actual resolver requires a nameserver that watches for the lookup itself. That is the probe test, and it is the reason this project exists.
Privacy
- Nothing about your visit is logged. No addresses, no resolver identities, no results, no visit counter.
- No third-party analytics. There is no script on this page from any domain other than this one.
- Your address is never sent to a geolocation vendor. Network details come from the edge that already terminated your connection, so no external lookup happens.
- Two disclosures, because they are real. The WebRTC test contacts Cloudflare's public STUN server — without it the test cannot see the exposure it exists to find. The DNS tests query Cloudflare, Google and dns.sb directly from your browser. Those three learn that someone asked them about a fixed public record, which is what they are for.
- No VPN affiliate links, now or later. The business model for most tools in this category is commission on the product they then recommend. That conflict is why their results are worth so little.
- Run comparison stays on your device. Your previous result is kept in your browser's local storage so the page can show what changed between runs — for example with your VPN on and off. It is never transmitted anywhere.