WHOIS is a protocol for querying databases that store registered domain name information. Understanding WHOIS data helps with domain research, brand protection, and cybersecurity investigations.
What WHOIS Records Contain
A WHOIS record includes the domain name, registrar (company where domain was purchased), registration and expiry dates, name servers, and registrant contact information. Historically, this included full contact details, but privacy regulations have changed what is publicly visible.
Registrant vs Registrar vs Registry
The registrant is the person or organization that owns the domain. The registrar is the company through which the domain was purchased (like GoDaddy or Namecheap). The registry operates the TLD itself (like Verisign for .com). WHOIS data comes from registrars and registries.
WHOIS Privacy and GDPR
Since GDPR (2018), most WHOIS records redact personal information for privacy. You will often see "REDACTED FOR PRIVACY" instead of names, emails, and addresses. Some registrars offer proxy services that replace owner info with the registrars contact details.
Important Date Fields
Creation date shows when the domain was first registered—older domains often have more authority. Updated date shows the last modification to the record. Expiry date is critical for monitoring domains you own or want to acquire when they expire.