Is there a central database of all domain registration information, or a way to access an aggregate of that data?

I know there are already tools to help you access the registration information of a specific domain, but I'm interested in a way to search all domain registration information to see all domains owned by one individual or company.

I've found paid tools that claim to do this, but their price is prohibitively expensive for the work I do, and I didn't know if there was a way to gain this information without a paid service.

  • become a domain registrar? Also, the answer will be different if you're looking at .com vs. net/org/edu/gov, one of the country tlds, or one of the newer vanity tlds. There's also a huge uptick in 'privacy services' to anonymize domain registrations and make it harder to tell who's the registrant.
    – Joe
    Commented Jun 5, 2013 at 14:22
  • I asked a similar question. Maybe it gives you a little bit more insight - after a long time: opendata.stackexchange.com/questions/15625/…
    – WeSee
    Commented Sep 12, 2019 at 8:47

1 Answer 1


You could try a service like http://www.whoisxmlapi.com/reverse-whois.php or http://www.domaintools.com/

The short answer is: it's complicated. The whois system (which is used to query domain registration data) is decentralized similarly to the DNS system - individual registrars keep the whois data for their clients so there isn't a meaningful way to query a central database. Additionally, the whois protocol is designed to be incredibly simple: query for a resource and receive the associated data. Think of it as a dictionary... You can easily search a dictionary for the definition of a word, but you'd need a different tool to search through all the definitions to find words with similar meanings. Companies like the ones mentioned above do the heavy lifting by aggregating the individual whois data and then providing a means of searching the meta data. Since not all whois responses are the same however, most results by reverse whois searches are considered "best guess."

As with everything, there are caveats to the explanation above, but without getting too unduly complicated - there you have it.

  • Thinking I might end up using the first tool (wasn't nearly as expensive as domaintools). I've been using a hacky approach to find this info by doing a "site:" search of the domaintools site with info of the original domain, which works okay, it just seemed like there "should" be an easier way to go through all of this, but like you said, someone else would have to do that heavy lifting of pulling all the info from all the registrars (which I assume is in the 1000s). Also: how the heck you find this? Commented Jun 4, 2013 at 23:01

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