---
title: "What is RDAP?"
url: "https://lookvalid.com/glossary/rdap.md"
canonical_url: "https://lookvalid.com/glossary/rdap"
last_updated: "2026-10-23"
type: "conceptual"
summary: "RDAP is the standard way to ask who registered a domain, IP block or ASN, answered as structured JSON over HTTPS."
related: ["https://lookvalid.com/glossary/whois.md", "https://lookvalid.com/glossary/domain-age.md", "https://lookvalid.com/glossary/asn.md", "https://lookvalid.com/products/domain-age.md", "https://lookvalid.com/products/ip.md"]
---

# What is RDAP?

RDAP is the standard way to ask who registered a domain, IP block or ASN, answered as structured JSON over HTTPS.

It replaces WHOIS, which returns free-form text with a different layout for every registry. RDAP gives machines predictable fields, such as registration and expiry dates, and supports redaction of personal data.

Registration dates from RDAP are the basis for domain-age checks.

Each registry runs its own RDAP server, and a bootstrap file published by IANA tells a client which one to ask for a given domain extension or address block. A lookup therefore takes two steps: find the right server, then request the record. Some registries limit how often a single client may query.

## Related

- [What is WHOIS?](https://lookvalid.com/glossary/whois.md)
- [What is Domain age?](https://lookvalid.com/glossary/domain-age.md)
- [What is ASN (Autonomous System Number)?](https://lookvalid.com/glossary/asn.md)
- [Domain Age API](https://lookvalid.com/products/domain-age.md)
- [IP Intelligence API](https://lookvalid.com/products/ip.md)