This tool checks domain name availability via RDAP (Registration Data Access Protocol) — the modern registry data standard that replaced WHOIS. Popular TLDs are checked: .com, .ru, .net, .org, .io, and more.
RDAP is an IETF standard (RFC 7480) that replaced the WHOIS protocol. It returns structured JSON instead of unformatted text, and supports authentication and access control.
rdap.org — a universal RDAP proxy;