WHOIS — Guide de recherche de domaine

WHOIS is a public query protocol providing registration information about domain names. Established in 1982 (RFC 812), it stores who registered a domain, creation and expiration dates, and nameserver information.

A WHOIS lookup shows:

• Registrant information — who registered the domain
• Registrar — where it was registered
• Important dates — creation, expiration, last updated
• Nameservers — DNS servers for the domain
• Status codes — transfer locks, active/suspended

Note: Since GDPR (2018), many registrars redact personal info.

Domain purchasing: Check owner willingness to sell by looking at creation date and usage. Competitive analysis: Research when competitors registered domains. Expiry monitoring: Track when valuable domains expire. Brand protection: Monitor for lookalike phishing domains.

RDAP (Registration Data Access Protocol) is gradually replacing WHOIS with structured JSON responses, better internationalization, and GDPR-compliant access control.