Whois Lookup

Whois is the oldest lookup service still in daily use: a plain-text protocol on port 43 that answers the question "who registered this name and when". Finding the right server takes two steps, and this tool does both. First it asks IANA, which keeps the master list of top-level domains and points at the registry responsible for each one. Then it asks that registry — Verisign for .com, KISA for .kr, Nominet for .uk — and shows you the answer exactly as it came back, with no reformatting.

What you get, when you get it, is the registrar the name was bought through, the creation date, the last update, the expiry date, the nameservers and a list of status codes. Those codes are worth learning: clientTransferProhibited means the owner has locked the domain against being moved to another registrar, which is a good sign rather than a problem; pendingDelete and redemptionPeriod mean the registration has lapsed and the name is on its way back to the pool; serverHold means the registry has taken it out of DNS entirely. The creation date is the single most useful field for judging a name you have never heard of — a domain registered eleven days ago that claims to be an established bank is telling you something.

The contact details are mostly gone, and it helps to know why rather than assume the lookup failed. Until 2018, whois for a .com printed the registrant's name, postal address, phone number and email for anyone who asked. When the GDPR came into force, that turned out to be a bulk publication of personal data with no legal basis, so ICANN moved to a redacted output: gTLD records now say REDACTED FOR PRIVACY where a person used to be, and offer a forwarding address or a web form instead of a real email. Access to the full record still exists for law enforcement and trademark holders through RDAP with credentials, but not for a casual query. Many registrars also sell privacy services that substitute their own details even where publication would be allowed.

Country-code registries each made their own decision, so results vary a lot by suffix. Korea's .kr, run by KISA, still returns the registrant name or organisation, the administrative contact and the registration and expiry dates in both Korean and English — a far more informative answer than any .com will give you today. Several European ccTLDs are stricter than the gTLDs and return almost nothing for individuals while publishing full details for companies. If a .com lookup here looks disappointingly empty, that is the correct current answer and not a fault in the tool.

Even redacted, whois remains the fastest way to check when a domain expires, which registrar to contact about abuse, whether a name is locked, and how old it is. Registries do rate-limit queries and some truncate long answers, so treat a sparse response as a hint to try again later rather than as proof that nothing exists. Only the domain name you type is sent to the server; no file is uploaded and no result is stored.