| Whois Freaks | API which allows you to search Whois-database (430M+ domains since 1986) by keyword, company name or owner name |
| Expireddomains.net | lists of deleted and expired domains (last 7 days) |
| InstantDomainSearch | search for domains for sale |
| WhoisDS.com | database of domains registered in the last day |
| API Domaindumper | An interesting tool for researchers of IT history and data journalists. Just an FREE API that shows how many sites were registered in each domain zone on a given day (since January 1, 1990) |
| ptrarchive.com | search by 230 billion DNS records retrieved from 2008 to the present. |
| PeeringDB | Freely available, user-maintained, database of networks, and the go-to location for interconnection data. |
| IQWhois | Search whois data by address, city, name, surname, phonenumber |
