WHOIS is a protocol for looking up the registration records of domain names, IP address blocks and Autonomous System Numbers. It answers questions like: who registered example.com, and when does it expire?
For IP blocks, WHOIS shows the network operator — usually an ISP or hosting provider — rather than an individual. Modern registries redact personal data under privacy regulations like GDPR.
Our WHOIS tools automatically discover and query the correct authoritative registry server from IANA data.