Who owns this domain?

What is WHOIS / RDAP?

RDAP (Registration Data Access Protocol) is the modern successor to the legacy WHOIS protocol. When you register a domain — or when an ISP gets allocated a block of IP addresses — the registration goes into a public registry. RDAP exposes that data over HTTPS as structured JSON, instead of the unstructured text format that the original 1982 WHOIS protocol used.

For gTLDs (.com, .net, .org and most others), ICANN required all registrars and registries to support RDAP by January 2025. Most Regional Internet Registries (ARIN, RIPE NCC, APNIC, LACNIC, AFRINIC) have supported RDAP for IP address lookups for several years.

Why is some data redacted?

Since GDPR took effect in 2018, registries and registrars have been required to suppress most registrant contact information from public lookups. You'll typically see the registrar, dates, name servers, and EPP status codes — but the registrant's name and email are usually replaced with the registrar's privacy proxy. The full data is still on file with the registrar; it's just not public.

What is reverse DNS?

A regular DNS lookup turns a hostname into an IP address. Reverse DNS turns an IP back into a hostname — the operator of an IP block can publish PTR records that say "this address is named mail.example.com." Reverse DNS is mandatory for mail server reputation, useful for traceroute readability, and a clue (though not a guarantee) about who runs a given address.

Known limitations

Some country-code TLDs — notably .de, .cn, .jp, .uk, .it, .ch, .kr, and .pl — have not adopted RDAP and still require legacy port-43 WHOIS. Cloudflare Workers can't open raw TCP connections to external servers, so this tool returns a clean error for those rather than fake-supporting them.

Registrant contact data is also frequently redacted under GDPR and ICANN privacy policies — that's a feature of the registry, not a limitation of this tool.