Site Search

The Registration Data Access Protocol (RDAP) is a computer network communications protocol standardized by the Internet Engineering Task Force. Developed as a successor to WHOIS, allows users to query for Registry data (domains, contacts, hosts and Registrars) over HTTPS.

More information on the history and development of RDAP can be found here.

Access Policy

Access to Neustar's RDAP Service is at all times governed by the RDAP Access Policy. By accessing the service you agree to be bound by the terms of the RDAP Access Policy.

User Guide

For information about how to use Neustar's RDAP Service, please review our RDAP Service User Guide.


How to access Neustar's RDAP Service

Any internet user may query the RDAP service, however responses for queries made by anonymous users may be redacted. Individuals and organisations with a legitimate interest in accessing domain name registration data may request authenticated user access to the RDAP service. To make a request for authenticated access, please visit: RDDSrequest.nic.neustar

How to use Neustar's RDAP Service

Most Neustar-supported TLD Registries will have an RDAP service on the hostname rdap.nic.[TLD], where [TLD] represents the applicable TLD you wish to query. For example, the .neustar RDAP service hostname is: rdap.nic.neustar. If you find that there is no response on a Registry's assumed RDAP host, it may be that the Registry Operator has not implemented an RDAP service. RDAP is an API and is intended for machine to machine interaction, as such there is no web-based interface available to submit RDAP requests at this time.


Help and FAQs

What is RDAP?

RDAP stands for Registration Data Access Protocol. It was developed by the technical community in the Internet Engineering Task Force (IETF) as a replacement for the WHOIS services. RFCs 7480, 7481, 7482, 7483, 7484, and 7485 define the behavior of RDAP.

How does RDAP differ from WHOIS?

RDAP is a HTTP-based protocol that delivers data in a standard, machine-readable JSON format. WHOIS is a text based protocol and, as it doesn't have standardized queries and responses, the interaction with Registries can vary significantly. While Registry lookup and search services have traditionally been offered through WHOIS, it has a number of shortcomings, including the lack of a standard data model, the lack of support for internationalization and the inability to authenticate users to provide differentiated services to such classes of users.

Do I need an RDAP client?

There are a number of RDAP clients currently available for use. Whether or not you require an RDAP clients depends on your needs and intended use of the RDAP service.

What is bootstrapping?

The IANA Bootstrap Service Registry publishes bootstrap files that provide the authoritative servers to query (this is called bootstrapping) for RDAP. The IANA Bootstrap Service Registry for Domain Name Space can be found here.

What are bootstrap files?

Bootstrap files are JSON files, as defined in RFC 7484. IANA publishes these files in their Bootstrap Service Registry for the Domain Name Space, as well as the IPv4 Address Space, IPv6 Address Space and Autonomous System Number Space.

How do I make a query?

The querying format for RDAP is {Service Host}/{Query} where {Service Host} is the hostname of the Registry's RDAP service and {Query} is the query that you want to submit. For example, a domain query for registry.neustar against the .neustar RDAP service would be: rdap.nic.neustar/domain/registry.neustar

What is the ICANN Operational Profile?

The 'Operational Profile' is defined by ICANN so that all RDAP services operate on a consistent basis. Neustar's RDAP Service implements the ICANN Operational Profile. More information can be found here.

For more information regarding the types and format of RDAP queries, please refer to our RDAP Service User Guide.


Learn How Your Company Can Benefit from the Power of Trusted Connections.

Contact Us Give us a call 1-855-898-0036