WHOIS Lookup

From WHOIS to RDAP

WHOIS is the original protocol for looking up domain and IP registration data, dating to the early ARPANET. It still works, but its plain-text responses vary wildly between registrars and registries, making automation painful. RDAP (Registration Data Access Protocol) is the modern replacement: a JSON-based, HTTPS-delivered, structured format that all major registries now support. This tool uses RDAP under the hood but presents the results in plain language.

What You Can Find

For a domain: registrar name, creation/expiry/updated dates, name servers, status flags (e.g., clientHold, pendingDelete), and abuse contact. For an IP address: the assigned organization, ASN (Autonomous System Number), CIDR range it belongs to, and country. Useful for domain expiry monitoring, security investigations, abuse reporting, and verifying that a domain or IP belongs to the entity you think it does.

Privacy and Redaction

GDPR and other privacy laws have led most registrars to redact registrant contact information for individuals. You will commonly see "REDACTED FOR PRIVACY" instead of names and email addresses — this is expected. The technical fields (registrar, dates, name servers) remain visible.

Building This Into Your Tooling

I help clients build security data pipelines, log enrichment workflows, and threat intelligence integrations that incorporate WHOIS, ASN, and geolocation lookups. Learn about ETL and data pipeline development, integration services, or get in touch.