---
title: "What is WHOIS?"
url: "https://lookvalid.com/glossary/whois.md"
canonical_url: "https://lookvalid.com/glossary/whois"
last_updated: "2026-10-23"
type: "conceptual"
summary: "WHOIS is the older protocol and record format for looking up who registered a domain or IP block."
related: ["https://lookvalid.com/glossary/rdap.md", "https://lookvalid.com/glossary/domain-age.md", "https://lookvalid.com/products/domain-age.md"]
---

# What is WHOIS?

WHOIS is the older protocol and record format for looking up who registered a domain or IP block.

A WHOIS answer is free-form text that differs between registries, and since privacy rules took effect most registrants' personal details are hidden. The registrar, creation date and name servers usually remain.

RDAP is its structured successor and is now the preferred way for software to ask the same questions.

A WHOIS answer comes from the registry for the domain's extension and, for some fields, from the registrar, so two lookups can show different details. Look at the creation date and the registrar first: they usually stay visible even when contact details are hidden, and they are what most risk checks rely on.

## Related

- [What is RDAP?](https://lookvalid.com/glossary/rdap.md)
- [What is Domain age?](https://lookvalid.com/glossary/domain-age.md)
- [Domain Age API](https://lookvalid.com/products/domain-age.md)