I work on a service that, among other things, validates user-provided information against the data retrieved via WHOIS. Most transactions are reasonably well handled by a few simple checks, but there's a long tail of records which have a different structure than most and require expensive manual intervention.

I've found definitions for the WHOIS protocol itself (RFC 3912), but nothing about the schema(s) of the data to be returned. Does such a thing exist and, if so, where?

  • 1
    There is no standardization for how WHOIS data should be displayed, just Extensible Provisioning Protocol (EPP) domain status codes. Registrars and Registries can otherwise return the data in any order or field name they chose. There's a number of server-side scripting modules (in Perl, Python, etc...) that try to parse these variations and return them in a uniform way (search Cpan for them).
    – dan
    Jun 7 '16 at 2:34

There is no schema per-say of the data and format which is returned through a whois query. Whois data is generally returned as simple text designed to be human readable. The companies that parse whois data to extract key information from it generally use regex searches to identify key field names in the string and extract the data after it to parse the data. There are a number of services online that provide programmatic whois api services which have done the heavily lifting of parsing the whois data and return it as an XML or JSON file. Sounds like this is what you may be looking for.


Your question depend on the TLD for which you query domain names through whois. Most gTLDs and specifically the ones from 2012 have to follow an ICANN mandated format. However ccTLDs have no such obligations and basically each one is doing its own thing.

In some future, RDAP may replace or at least coexist with whois, and RDAP uses a specific JSON structure for replies, so it is easier to parse (it was built exactly for that, among other things).

Also depending on the TLD, you may have access to other kind of data structures and/or sources. For example, some registries provide opendata (but not necessarily real time fresh).

Again, without the TLDs concerned, it is hard to give you tailored replies.

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