Domain lookup (ICANN RDAP)

This is the same data lookup.icann.org shows, fetched straight from the registry that runs the domain's top-level domain using RDAP (Registration Data Access Protocol), the structured replacement for WHOIS. We find the right registry server through IANA's bootstrap list, so the answer is authoritative rather than a copy. Enter any host name; we look up its registrable domain.

What to look for

• Expires. The date the registration lapses unless renewed. Most registrars auto-renew, but an expired card or a departed colleague's account breaks that silently. Everything on the domain, certificates included, stops working when it goes.
• Status. clientTransferProhibited is the normal, healthy transfer lock. clientHold or serverHold means the domain has been taken out of DNS, often for unverified contact details. pendingDelete and redemptionPeriod mean it has already expired.
• Name servers. Should match what your DNS provider gave you. A mismatch after a migration is a common cause of a site that works for some visitors and not others.
• DNSSEC. Signed means the registry holds DS records for the zone. Unsigned is the default for most domains and is not an error.
• Registrant. Since 2018 most registries redact personal data; a redacted registrant is normal. The abuse contact is the registrar's, for reporting misuse.

Why RDAP instead of WHOIS

WHOIS is a 1982 text protocol with no standard format, which is why every WHOIS client is a pile of regular expressions. RDAP returns JSON with defined fields, works over HTTPS, and is what ICANN requires of every gTLD registry. Some country-code registries have not adopted it yet; for those the lookup reports that no RDAP server is listed.