reverse whois

whois api lets you quickly lookup a domain name's whois data. you get fully parsed whois fields in xml or json format at just $2 per 1000 domains!

domainiq provides a comprehensive set of tools for whois and domain name research, specifically tools that assist in brand protection, cyber crime investigation, counter-terrorism research, and domain investment research.

reverse whois lookup. this free tool will allow you to find domain names owned by an individual person or company.

check all network relations between domains sharing the same ip address, ns and mx records and whois data. powered by a database of 765+ million domain names.