WHOIS is a query protocol running over TCP port 43 that returns registration data for domain names and IP addresses. Every registered domain has a WHOIS record maintained by its registrar, covering the registrar name, key dates, domain status, name servers and — where not redacted — contact details.
What Is Inside a WHOIS Record?
- Registrar: the company that processed the registration (GoDaddy, Namecheap, Alibaba Cloud…).
- Created / Updated / Expires: the three key dates of the domain lifecycle; after expiry there is usually a ~30-day renewal grace period.
- Domain Status: e.g.
clientTransferProhibited,redemptionPeriod— key signals when buying or transferring a domain. - Name Servers: which DNS servers answer for the domain; parked/for-sale domains usually point to parking nameservers.
- Registrant Contact: name, email, phone. Post-GDPR most registrars redact these by default.
WHOIS vs RDAP
RDAP is the IETF successor to WHOIS: HTTPS + JSON based, with authentication, pagination and standardized fields. ICANN has required gTLD registries to operate RDAP since 2019. ABC Lookup tries RDAP first and falls back to port-43 WHOIS when a TLD has no RDAP endpoint.
How to Look Up WHOIS
Type any domain on the ABC Lookup homepage (URLs with protocol, paths and subdomains are normalized automatically) and get full WHOIS data in about a second, plus for-sale detection, ICP filing check, GFW check and archive history. Bulk lookup supports up to 500 domains per batch for whitelisted IPs.