Domains and WHOIS

What is RDAP, and how is it different from WHOIS?

WHOIS is a 1982 protocol that returns free text over an unencrypted port. RDAP returns structured JSON over HTTPS, with a defined schema and the ability to tell an authenticated requester from an anonymous one. That last capability is the reason it won.

RDAP — the Registration Data Access Protocol — is the modern replacement for WHOIS: it returns structured JSON over HTTPS instead of free text over port 43, it supports internationalised names properly, and it can vary its response by who is asking. Since 28 January 2025, gTLD registries and registrars are no longer obliged to run the legacy WHOIS service at all, so a growing number of domains answer only over RDAP. Any lookup tool that still returns results is either speaking RDAP or proxying something that does.

Worked out 2026-09-10 (IST) · RFC 7480–7484 and RFC 9083; ICANN gTLD RDAP profile

Side by side

WHOIS and RDAP compared
	WHOIS	RDAP
First specified	1982 (RFC 812), refreshed 2004 (RFC 3912)	2015 (RFC 7480–7484), updated 2021 (RFC 9083)
Transport	TCP port 43, plain text, unencrypted	HTTPS, encrypted
Response format	Free text, different at every registry	JSON, one schema everywhere
Field names	By convention only	Defined by the specification
Internationalisation	Undefined; encoding varies	UTF-8 throughout, with IDN support
Differentiated access	Impossible — everyone gets the same answer	Yes, by authentication
Standard error handling	None	HTTP status codes
Referrals to the registrar	Ad hoc text line	Structured links member
Required for gTLDs	No, since 28 January 2025	Yes

The bootstrap problem, solved

With WHOIS you had to know which server to ask: whois.verisign-grs.com for .com, whois.registry.in for .in, and so on, then follow a text referral to the registrar for the detail. RDAP replaced that guesswork with an IANA bootstrap registry that maps every TLD to its RDAP base URL, so a client resolves the right endpoint automatically and follows a structured link to the registrar.

What has not changed

RDAP is a transport upgrade, not a privacy change. The registrant fields that GDPR made non-public are just as redacted in an RDAP response as in a WHOIS one — you get a redacted member telling you which fields were removed and why, which is more honest than the old blank line, but not more revealing. If you want the data behind the redaction the route is still a disclosure request, not a different protocol.

Sources: ICANN Registrar Accreditation Agreement 2013, ICANN Transfer Policy, ICANN Expired Registration Recovery Policy, ICANN Registry Agreement Specification 4 (RDAP), IETF RFC 9083 and RFC 5731 (EPP status codes), and the EU General Data Protection Regulation as applied by ICANN’s Registration Data Policy.

Check your own numbers

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Frequently asked

Is WHOIS dead?

For generic TLDs it is on the way out: since 28 January 2025 ICANN no longer requires registries and registrars to operate the port-43 service, and many have switched it off. Country-code registries set their own timetable and several still run WHOIS as the primary interface. In everyday speech "WHOIS lookup" now usually means an RDAP query presented in the old familiar layout.

What does an RDAP response actually look like?

A JSON object with named members - objectClassName, ldhName, status as an array of EPP codes, events carrying registration, expiration and last-changed dates, entities carrying roles such as registrar and abuse, and nameservers as an array. Because it is schema-defined rather than free text, two registries return the same field in the same place, which was never true of WHOIS.

Can RDAP show me more data than WHOIS did?

It can, and that is the point of it. RDAP supports authenticated access, so a registry can return a redacted record to an anonymous query and a fuller one to a verified law enforcement or contracted-party request. WHOIS had no way to distinguish the two, which is precisely why the GDPR answer had to be to hide everything from everyone.

Do I need to change anything to use RDAP?

Not as a person - use any lookup tool and it handles the protocol for you. If you script lookups, replace port-43 queries with an HTTPS GET to the bootstrap service at rdap.org or to the registry RDAP base URL listed in IANA's bootstrap registry, then parse JSON instead of scraping text.

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