Reverse WHOIS tools to find domains by registrant data | WhoisXML API

Reverse WHOIS tools and services help you find domain names connected by a registrant identifier

Reverse domain queries via lookups or API calls are useful to identify all domain records that correspond to search terms like a name, an email address, a phone number, etc.

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721 Million+Domains tracked
14.3 Billion+WHOIS records
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Reverse WHOIS queries by registrant data can be done through:


Use our handy lookup web interface to query your search term of interest and get a list of all domain names found in the last 7 days (i.e., for which the term appears in the domains’ WHOIS records). Include and exclude certain terms with the advanced lookup option.

Reverse WHOIS Lookup | WhoisXML API
Reverse WHOIS API | WhoisXML API


You can use Reverse WHOIS API to list linked domain names via API calls. We provide documentation and client libraries to facilitate integration.


  • Establish all known domain name associations with individuals and organizations. Learn more about domain footprints with the consumption model — lookup or API — of your choice.

  • Narrow down your search results by employing filtering parameters to exclude terms that are not relevant to your query.

  • Go with any WHOIS detail you have on hand to run queries via Reverse WHOIS Lookup and make API calls with Reverse WHOIS API. You can use exact-match terms or fuzzy ones for broader results.

  • Results from our lookup tool and API are gathered from the most comprehensive historical WHOIS database on the market with daily updates. All the data returned is parsed, normalized, and consistently formatted.

Conduct advanced reverse WHOIS queries by registrant identifiers and much more with the Domain Research Suite (DRS) dashboard.

Fast, intuitive and responsive.

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Reverse WHOIS Search | Domain Research Suite | WhoisXML API
Reverse WHOIS Overview | WhoisXML API

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