Things you need to know about Whois Data - FAQs | WhoisXML API

WhoisXML API Blog

Things you need to know about Whois Data - FAQs

Each day we get lots of queries with regards to the use, functionality and various other technical details of

In order to clarify the doubts of our new customers as well as long-standing patrons, we have decided to run a series of blogs on various important topics. We will dedicate each blog to a particular topic and will feature the most frequently asked questions in detail.

The first topic in this series will cover Domain Data. Now, it may sound like an elementary topic, but trust us, there are so many misconceptions and misunderstood facts, that starting from the basics is the only way to clearly understand Whois data!


Which Top Level Domains (TLDs) are supported by

Answer supports over 1500 TLDs, covering almost all the TLDs that are available, which includes:

  • Generic Top Level Domain (gTLDs): These are usually three or more letters, and are widely known and used e.g. .com, .net, .gov, .org etc. covers all the sub-categories
    within these gTLDs; i.e. sponsored and unsponsored TLDs, restricted and unrestricted TLDs.
  • Country Code Top Level Domains (ccTLDs): These are usually two letters, and are used by individuals or companies from a particular geographic region e.g. .gb, .us, .eu etc. ccTLDs help
    identify the country, sovereign state, or a dependent territory the domain is registered with.
  • Infrastructure Top Level Domains: This has only one TLD i.e ARPA (Address and Routing Parameter Area). As one of the original TLDs, it is used exclusively for internet infrastructure

You can check the detailed list of all TLDs we support here


In what format will the Whois data be made available?

Answer provides well-parsed data in XML and JSON format. Also, the data elements are normalized and provided in a consistent arrangement. Besides this, the original raw data is also a part of all the query results.

We also offer bulk downloads of domain data for research and analytic purposes. The database downloads are available as MySQL dump or CSV files.


How often are the domain details refreshed at


All the available domain details are updated at regular intervals. The data age ranges from 0 to 24 hours, ensuring that only the most up to date and accurate information is available.

Alternatively, if a person is interested in getting real time domain data, a query request can be made with an additional flag and the data that is returned will be refreshed at the time of sending.


How is the parsed data from better than the raw data available from Whois web search?


Whois web search delivers raw data, i.e. unstructured Whois data obtained, as is, from the registry / registrar. Important data elements such as registrant name, email, phone number, address, etc. are lost in the raw text, making it difficult to utilize this information easily.

To add to it, this raw data does not have any consistency, as each registrar/ registry may use different formats, especially with regards to numerical data, i.e. date, time, phone number. A lot of time and effort is wasted in parsing this data for further processing and analysis. delivers well-parsed data, which is extracted from this raw Whois record. Once the Whois record is parsed, important elements are grouped together and returned in a well-structured format. In addition to this, various data elements are normalized in a consistent format, for example; date, time, phone numbers, address, and other elements. This helps various tools in utilizing data elements efficiently.

This parsed data is available in XML and JSON formats.

With our extensive experience and in-depth knowledge of domain data, we ensure that every Whois record is well parsed, consistent and up to date.


How is Reverse WhoisXmlApi search different from the normal WhoisXmlApi search?


WhoisXmlApi search is used to find domain related data. For this, a query with a domain name has to be made and the search returns its Whois record, which usually includes the name of the registrant, company name, domain registration date, email address, physical address, expiry date, etc.

Reverse WhoisXmlApi search is used to find domain records connected to a particular search term(s). For this, a query with a search term(s) has to be made; such as name, email, phone, address or any other term(s) that are used in a Whois record, and the search returns all the domain records that correspond to the search term(s).

For instance, if you make a query for an individual’s name in Reverse WhoisXmlApi search, then all the domains that feature that particular individual’s name will show up.

Reverse WhoisXmlApi search, you can also make a query on an IP address and the search will return all the domain records related to that particular IP.

To learn more about Reverse WhoisXmlApi search, click on the link here


Why is the response showing elements for some domains under WhoisRecord, while for some under WhoisRecord->registryData? Is some data missing or is there any difference between the two?


No, there is no data missing but there may be a slight difference between the two sections as they are obtained from two different sources.

To elaborate, domain details are maintained by a Registry, who accredit various Registrars to provide registration services to the public. The registrars, after getting all the information and registering a domain, share each domain record with the registry. Hence, every domain usually has up to two Whois record, one from the registrar (who may or may not share their registrant information) and one from the registry (who usually provide at least some information connected with a domain).

WhoisRecord (the root element) represents the Whois data collected from the registrar and WhoisRecord->registryData represents data collected from the registry. Having the same origin, both the sections of the Whois record are almost identical in structure and content.

The inconsistencies may occur as certain gTLDs (eg. most .com and .net) provide both the Whois records (from the Registrar and Registry) while most ccTLDs (eg. most .uk, .eu, .in, .us) share only WhoisRecord->registryData (from the Registry). Usually, all the data elements will not be available in both the records and the elements shown depends on the Whois records that are returned, for that domain, from their source.

Hence, it's recommended to look under both, WhoisRecord and WhoisRecord->registryData, to get all the required information.

That’s it for now! We will be back soon and keep you posted on various aspects and features of Meanwhile, if you have any questions or need more information about, please post them in the comment box below and we will get back to you as soon as we can.
Finally, do subscribe to our blog to get periodical updates about and also the latest happenings in the domain world!

Try our WhoisXML API for free
Get started