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Domain Registration Data: Advanced Lookup Functionality Now Available

2 August 2021

ICANN organization (org) has made enhancements to its registration data lookup tool to increase functionality and improve user experience. The lookup tool gives users the ability to look up current public registration data for domain names and Internet number resources, like the availability of a specific domain name or the date a domain name was registered. And now, users can perform lookups of autonomous system numbers (ASNs) and Internet Protocol (IP) networks. To explore the lookup tool's added features, click here.

With the lookup tool's new functionality, users can now enter an ASN or IP network (also supported using Classless Inter-Domain Routing notation) in the tool's search box and perform a lookup for the corresponding registration data as made available by the authoritative Regional Internet Registry (RIR). Additional updates have also been made to improve user experience, including a clearer delimitation of the information shown for each contact in the Registration Data Access Protocol (RDAP) response, support for vCard format extensions as documented in RFC 8605, and properly indicating to the user when connectivity issues occur while trying to reach the corresponding RDAP server.

Access to public registration data information helps enhance registrant accountability. It also provides key information that is needed when reporting technical issues or abuse practices related to a specific domain name or IP address. These are just a few examples of how access to public registration data can help maintain a healthy Internet ecosystem.


ICANN org developed the registration data lookup tool as a free public service. It is based on RDAP, a protocol developed by the technical community in the Internet Engineering Task Force (IETF). This next-generation protocol delivers registration data like WHOIS does, but with improved standardized query and response formats. RDAP has several other advantages over the WHOIS protocol, including support for internationalization, secure access to data, and the ability to provide differentiated access to registration data.

Questions regarding the lookup tool or RDAP should be directed to globalsupport@icann.org.


Eduardo Alvarez

Director, Technical Services Operations