What is WHOIS used for?

WHOIS looks up who registered a domain, which registrar it was bought through, when it expires, and which nameservers it currently uses — useful for due diligence, abuse investigation, and troubleshooting delegation.

Why is the registrant's information hidden?

ICANN's Temporary Specification, adopted after the EU's GDPR took effect in 2018, requires registrars to redact personal data by default. Most registrars apply the same redaction worldwide rather than run two systems.

What is RDAP and how is it different from WHOIS?

RDAP (Registration Data Access Protocol) is the structured, JSON-based successor to WHOIS's free-text format, standardized by the IETF and now mandatory for gTLD registries. It answers the same question with machine-readable data.

What Is WHOIS?

WHOIS is the lookup protocol that answers one question: who registered this domain, and through which registrar? It has existed since the early internet, long before privacy regulation caught up with it.

What a WHOIS Record Contains

A WHOIS record is published by the domain's registry and registrar. Regardless of what is hidden, it always includes:

Registrar — the company the domain was bought through (e.g. Namecheap, GoDaddy, OVH)
Creation, updated and expiration dates
Nameservers currently delegated for the domain
Domain status codes (see below)
Registrant, admin and technical contact — often redacted, see next section

Why the Owner's Details Are Usually Hidden

Until 2018, WHOIS records typically showed the registrant's real name, address, email and phone number in full. ICANN's Temporary Specification, adopted after the EU's GDPR took effect, requires registrars to redact personal data of individuals in the EEA by default — and most registrars now apply the same redaction globally rather than maintain two systems.

What you see instead is usually the registrar's own privacy-proxy contact, or simply "REDACTED FOR PRIVACY". Businesses can still choose to publish their real details, and some country-code registries have their own, stricter or looser rules.

Common Domain Status Codes

Status codes describe what can and cannot currently be done to a domain:

Code	Meaning
`clientTransferProhibited`	The registrar has locked the domain against transfer to another registrar — the normal, safe default.
`clientHold`	The domain is suspended and removed from the DNS zone, usually for a billing or abuse issue.
`pendingDelete`	The domain was not renewed and is in its final redemption window before release.
`ok`	No pending operations or restrictions.

WHOIS vs. RDAP

WHOIS is a plain-text protocol from 1982 with no standard output format — every registry formats its response slightly differently, which is why WHOIS parsers are notoriously fragile. RDAP (Registration Data Access Protocol) is its structured, JSON-based replacement, standardized by the IETF and now mandatory for gTLD registries. It answers the same question but returns machine-readable, self-describing data.

Check a Domain

Run a WHOIS lookup →Next: What are nameservers? →

Try it on your domain

See the theory in practice — run a WHOIS Lookup for your own domain.