Compare software

IP Lookup vs Who.is: catalog facts
IP Lookup	Who.is
Free Free and open source under the GPL.	Freemium Lookups are free; domain history reports and monitoring are paid services.
Linux	Web
Simple single-purpose interface Adaptive layout for Linux phones	WHOIS, RDAP, DNS and IP lookups in one site Reverse nameserver lookup
Linux only Limited to IP information lookups	Full domain history requires a paid report Monitoring is a premium service
Downloadable app	Web application, Hosted service
Open source	Closed source
License: GPL-3.0-or-later	License not stated
No account needed	Not stated if an account is needed
Needs internet	Needs internet
Official website Full listing and sources Checked October 1, 2026	Official website Full listing and sources Checked September 23, 2026

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