DomainTools API Guide: Whois History

The DomainTools API is organized into distinct products with queries that follow a REST-ful URL structure wherever possible. Each product offers free, un-authenticated access for the sample URLs listed with each product. If you haven't already, you may want to review the getting started document to learn about authentication and response formats.

The Whois History API provides a list of historic Whois records for a domain name. The format for each record is similar to that returned by the Recent Whois API although some fields may be missing if the data was not available when the record was stored in our system.

  http://api.domaintools.com/v1/domaintools.com/whois/history/
	

The API does not include Whois records with identical data unless those records are necessary to understand the history of the domain name. For example, consider this hypothetical domain history:

• A domain name is registered in January 2010. DomainTools stores that initial Whois record.
• The contact information for that domain name changes in February 2010 and DomainTools stores the new record.
• No changes are made to that record for the next several months; however, DomainTools continues to store identical snapshots of the record.
• The domain name is sold in August 2010 and DomainTools stores the new ownership record.

In this scenario, the API would return four records: one for the initial registration, one for the February update, one representing the last record archived for the first owner, and one showing the first record after the sale. You can interpret this data in the following way:

• The time between the first and third records indicates length of ownership.
• The dates on the second and third records tell you when no changes occurred.
• The third and fourth records indicate a time window when the ownership of the domain changed.