Glossary
DOMAINS

WHOIS

The legacy plain-text protocol for querying domain registration data — registrant, registrar, dates, nameservers. Being superseded by RDAP.

WHOIS is the original protocol for querying domain registration information: registrant, admin/tech contacts, dates, nameservers, status. Defined in RFC 3912, it’s a plain-text TCP-port-43 protocol dating from 1985.

What WHOIS Returns

  • Registrant name and contact (redacted for most TLDs under GDPR since 2018)
  • Registrar of record
  • Creation, expiry, updated dates
  • Nameservers
  • EPP status codes
  • DNSSEC signing status

The GDPR Problem

Post-GDPR (2018), most gTLD registrars redact personal contact data by default. WHOIS still works — you just see REDACTED FOR PRIVACY or the registrar’s proxy contact instead of the real registrant. Access to unredacted data requires a legitimate-interest request through the registrar.

Query Path

whois example.com
   → connects to whois.iana.org (the source-of-truth referrer)
   → follows referral to whois.verisign-grs.com (for .com)
   → follows further referral to whois.registrar.com
   → returns final record

Being Replaced By RDAP

WHOIS is gradually being replaced by RDAP — a JSON/HTTP-based successor with proper authentication, structured data, and internationalized-content support. Most TLDs now serve both.

Check the RDAP glossary entry, the EPP glossary entry, and the TLD entry.

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