Privacy

There are no accounts, no login, and no database. DNSLens keeps no history of what you look up, because there is nowhere for it to keep one.

Your queries do leave your device — they have to, that is what a DNS lookup is. They go to the public resolver you pick, over HTTPS, straight from your browser. Any page telling you your DNS query never leaves your device is describing something that cannot happen.

Nearly every tool here works the same way: your browser makes an HTTPS request to a public DNS-over-HTTPS resolver, and DNSLens decodes the answer locally. The request goes from you to that resolver. It does not pass through any server of ours, and we never see it.

The resolver does see it: the name you asked about, the record type, and your IP address. What they do with that is set by their own privacy policy, which is linked beside each one in the picker. The three offered are Cloudflare, Google Public DNS and DNS.SB.

The subnet calculator and the IP and URL tools make no request at all. Those genuinely do run entirely in your browser, which is why they are the only place that claim is made.

The delegation trace is different, and it is the only part of DNSLens that touches our server. A browser cannot open a UDP socket, so it cannot query a root server directly. The trace therefore runs on our side: it sends the name and record type you gave, and the server makes the real queries from the root down.

For that endpoint, the name you traced is in the request. It is not written to a log we keep, not stored, and not associated with you. Your IP address is used to hold a rate limit in memory for a minute, because a trace makes real queries to real nameservers and should not be free to run without limit. Nothing survives that minute.

The delegation check uses the same endpoint, since it needs a genuine referral to compare against.

If analytics are enabled on this deployment, they record which pages were viewed and nothing else. No domain you look up, no IP address you check, no DNS response, no SPF record, no DKIM selector, and no trace target is ever sent to them. Those values stay in the page.

Your theme preference, in local storage, so the page does not flash the wrong colours on the next visit. That is all. No cookies are set. Clearing your browser's storage for this site removes it.

Lookup results live only in the page you are looking at. Reloading loses them. A lookup link carries the query in the URL, so opening one runs the lookup again rather than showing you a stored copy of somebody's result.

It will not scan ports, brute-force subdomains, attempt zone transfers, sweep network ranges, or send traffic anywhere you name. The trace endpoint accepts a domain name and a record type and nothing else — no server address, no port — which is what keeps it from being usable as a relay.

It also will not label a measurement as something it is not. An HTTPS round trip is called a round trip, never a ping. A recursive resolver's answer is never presented as a delegation trace.