WHOIS

WHOIS is a long-standing query system for looking up registration data associated with Internet resources such as domain names.

Format
Domains & DNS
Updated
Updated
Glossary Domains & DNS
WHOIS Aliases: registration data, domain lookup, RDAP.

Definition

WHOIS is a long-standing query system for looking up registration data associated with Internet resources such as domain names.

How it works

Ask WHOIS about a domain and you can learn its registrar, status codes, nameservers, and key dates. What you will rarely see anymore is personal contact information — privacy regulation and proxy services have redacted most of it. For generic TLDs, the aging WHOIS protocol has also formally given way to RDAP, its structured successor, though the familiar name persists.

Example: A lookup shows which registrar sponsors a domain and when its current registration expires.

Often confused: WHOIS shows registration data about a domain; it is not DNS, and a tidy record proves nothing about a website's trustworthiness.

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Sources

Last reviewed 2026-07-19.