Network

IP WHOIS Lookup

Look up WHOIS information for any IP address using the RDAP protocol. View the owning organization, network range, country, registration dates, and abuse contact.

When to use WHOIS lookup

  • Spam / intrusion investigation: When a suspicious IP appears in your logs, look up the owning organization and abuse contact to file a report.
  • Network administration: Verify the subnet range and registered owner of an IP block.
  • Confirm CDN / cloud providers: Look up well-known IPs like Google's 8.8.8.8 to verify their owner.
  • RDAP (Registration Data Access Protocol) is the modern replacement for WHOIS, returning structured JSON over HTTPS.

FAQ

No. Private and reserved addresses are not routable on the public internet and have no WHOIS records. Only public IP addresses can be looked up.

Results are cached for 24 hours. Wait a while and try again, or check rdap.org directly for real-time data.

Yes, both IPv4 and IPv6 addresses are supported.

RDAP data varies by registry (ARIN, RIPE, APNIC, etc.). Not all fields are populated for every IP block.
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Side Note — WHOIS history and the GDPR turning point

WHOIS was born in 1982 as RFC 812 during the ARPANET era. Originally a small database to identify who managed each computer, it grew into critical infrastructure as the commercial internet expanded.

The GDPR's enforcement in 2018 fundamentally changed domain WHOIS. Registrant contact details became protected as personal data, and most registrars began redacting them. IP address WHOIS (RDAP) was less affected since it primarily records organizational data, and most IP block registration information remains publicly accessible.

RDAP (Registration Data Access Protocol) is now the standardized successor to WHOIS. Unlike WHOIS which used plain text over port 43, RDAP operates over HTTPS with JSON responses, supporting authentication, access control, and internationalization. This tool uses RDAP.

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