Registration Data Access Protocol (RDAP)

>>> Click here for the experimental RDAP web client! <<<

>>> Click here for the RDAP deployment dashboard! <<<

The Registration Data Access Protocol (RDAP) is the successor to the ageing WHOIS protocol. Like WHOIS, RDAP provides access to information about Internet resources: domain names, autonomous systems, and IP addresses.

Unlike WHOIS, RDAP provides:

  • A machine-readable representation of registration data;
  • Differentiated access;
  • Structured request and response semantics;
  • Internationalisation;
  • Extensibility. aims to support users and developers of RDAP clients by providing a single end point for RDAP queries. aggregates information about all known RDAP servers. RDAP clients can send RDAP queries to, which will then redirect requests to the appropriate RDAP service.

How To Use

Client Implementers

If you are developing an RDAP client, configure it to send HTTP requests to<type>/<object>, where <type> is the object type (one of domain, ip, autnum etc) and <object> is the object identifier (eg,, 64496, etc).

HTTP Status Codes

  • 302 – occurs when knows of an RDAP service which is authoritative for the requested resource. Follow the URL listed in the Location header.
  • 400 – occurs when receives an invalid request (malformed path, unsupported object type, invalid IP address, etc).
  • 404 – occurs when doesn’t know of an RDAP service which is authoritative for the requested resource.
  • 429 – occurs if you have exceeded the rate limits.
  • 500 – occurs when is broken in some way.
  • 504 – occurs if needs to refresh the IANA bootstrap registry, but cannot.

Rate Limits will return a 429 response if you send more than 30 requests in a 300-second (5 minute) window.

If you are interested in doing high-volume data mining of registration data, please (a) don’t, but if you must, (b) consume the IANA registries directly. Net::RDAP::Registry, which is part of Net::RDAP, provides a simple interface to these registries.

Additional Services

  • ICANN-accredited registrars – you can obtain RDAP records for all ICANN-accredited registrars at{NNNN}-iana where {NNNN} is the IANA ID. These records are synthesised from data published by IANA and ICANN (Git repository).
  • Top-level domains – each TLD has its own RDAP record at{TLD}. This data is generated from the IANA whois (Git repository).


Privacy Considerations

If you use to perform RDAP queries, your queries will be logged, alongside your IP address. These logs are not disclosed to anyone and are deleted within a few months of being generated. will (apart from the subdomain) not set any cookies in your browser.

Submit Feedback

If you would like to submit feedback, or operate an RDAP service that you would like to be added to, please click here.

About is maintained by Gavin Brown.

You can review the code which uses on GitHub.