WhoAPI is a service for mass domain lookups that provides details about each domain to the user.
Details include domain availability check, domain owner details, server uptime status, blacklist listings check, screenshot, DNS zone, GEO, ranks. The API uses RESTful calls and responses are formatted in XML, JSON and TXT.
WHOIS is a protocol, most often used for querying databases that store information about owners of various Internet resources. When WHOIS is combined with WhoAPI it can become a powerful tool. This article explains how to use WHOIS and offers a number of use cases for using WHOIS with the WhoAPI.