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DomainTools Whois LookupWhoisThisDomain
Freemium

Basic lookups are free, with deeper history and reverse WHOIS research on paid plans.

 Free

Freeware from NirSoft, free to use and redistribute unmodified.

Web Windows
  • Domain ownership and IP address history in one lookup
  • Shows whether a domain is available or for sale
  • Chooses the WHOIS server automatically by TLD
  • Batch lookups and name-and-extension combinations
  • Free tier is limited
  • Historical and reverse lookups are aimed at paying users
  • Only queries WHOIS servers on port 43, not web-based WHOIS
  • Proxy authentication with a user name and password is not supported
Web application Downloadable app
Closed source Closed source
License not stated License: Freeware
Not stated if an account is needed No account needed
Needs internet Needs internet

Checked September 23, 2026

Checked October 8, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.