RDAPLookup
Reading room

Notes on registration data.

Practical context for using RDAP and understanding what a registry response can, and cannot, tell you.

Read an RDAP result

Learn which fields matter in domain, IP address, and ASN records.

September 13, 2026

How to Read a Domain RDAP Response

Learn how to read a domain RDAP response, including statuses, entities, events, nameservers, DNSSEC, notices, redaction and jCard contact data.

September 17, 2026

How to Read an IP Address RDAP Response

Learn how to read an IP address RDAP response, including network ranges, CIDR blocks, allocation hierarchy, RIR data, entities and abuse contacts.

September 18, 2026

How to Read an ASN RDAP Response

Learn how to read an ASN RDAP response, including autnum ranges, registration status, entities, RIR data and the limits of routing attribution.

Investigate an incident

Find the right registration contact and understand the limits of the record.

September 21, 2026

Why an RDAP Lookup Fails in a Browser

Learn why a browser-based RDAP lookup can fail because of CORS, endpoint errors, redirects, rate limits or invalid responses, and how to identify the failure without mistaking it for missing registration data.

Find or query a service

Trace authoritative endpoints and work with them outside the browser.

September 13, 2026

How to Query an RDAP Server with cURL

Learn how to query RDAP servers with cURL, follow redirects, inspect HTTP errors, format JSON with jq and look up domains, IPs and ASNs.

Build or migrate a client

Understand the protocol, monitor changes, and adapt to registration data standards.

September 27, 2026

How to Monitor Registration Changes with RDAP

Learn how to monitor domain, IP address, and ASN registration changes with RDAP using authoritative discovery, semantic snapshots, classified errors, responsible polling, and evidence-based alerts.