Every domain name has an owner, a registration date, and an expiry date. WHOIS is the protocol and database that stores this information publicly — and it is free to query.
What Is WHOIS?
WHOIS (pronounced "who is") is an internet protocol storing registration data for domain names, IP addresses, and autonomous systems. Created in 1982, it remains one of the most useful tools for investigating domain ownership.
What Does WHOIS Show?
- Registrant information — Owner name, organization, email and address (often redacted under GDPR)
- Registrar — The company the domain was registered through
- Registration date — When the domain was first registered
- Expiry date — When the domain registration expires
- Name servers — Which DNS servers are authoritative for the domain
How GDPR Actually Changed WHOIS
Before 2018, WHOIS records typically showed a domain owner's real name, email, phone number, and physical address in full public view. When GDPR took effect, ICANN required registrars to redact most personal data for domains registered by individuals in the EU, replacing it with generic registrar contact information — which is why so many WHOIS lookups today show "REDACTED FOR PRIVACY" instead of an actual name, even for domains that never explicitly opted into privacy protection.
WHOIS Isn't Actually One Database
There's no single central WHOIS server — each domain registry (Verisign for .com, PIR for .org, and so on) runs its own WHOIS server, and a lookup tool has to know which registry to query based on the domain's extension. This is also why WHOIS data formatting is notoriously inconsistent between different TLDs: a .com record and a .io record can present the same underlying information in completely different layouts, since there's no single enforced standard across registries.
How to Run a WHOIS Lookup
Use Anonymiz WHOIS Lookup — enter any domain name and get the full registration record instantly. No account required, completely free.
Common Uses for WHOIS
- Check domain availability — See if a domain is taken and when it expires.
- Identify website owners — Useful for business research and outreach.
- Investigate suspicious domains — Check registration date and registrar for phishing domains.
- Monitor your own domains — Verify registration details and expiry dates.
