An RDAP lookup answers the questions you used to take to WHOIS: who is the registrar, when was the domain created, when does it expire, which locks are on it and where its DNS is hosted. The data is the same. What changed is the format and how the query finds the right server.
ICANN’s page on the Registration Data Access Protocol describes it as “the replacement for the WHOIS protocol”, developed by the IETF, which “delivers WHOIS-like registration data, but in standardized data access and query response formats.”
RDAP vs WHOIS: what actually changed
The key date, in ICANN’s exact words: “All gTLD registries and registrars are required to provide RDAP services using the gTLD RDAP Profile, but as of 28 January 2025 they are no longer required to provide WHOIS services (except for .com, .name, and .post).” That is not the same as WHOIS being switched off. Some operators still run it; Cloudflare says it “currently provides both WHOIS and RDAP search capability”.
ICANN’s FAQ is clear that the content is unchanged: “The registration data is the same, but the structure of the response is different.” The reasons for replacing WHOIS were its “lack of support for internationalization, secure access to data, differentiated access, standardized query, response, and error responses”.
| WHOIS (port 43) | RDAP | |
|---|---|---|
| Format | Free text, varies by server | “standardized data access and query response formats”; JSON (RFC 9083) |
| Finding the server | You query a specific database | “bootstrap” routes the query “to the authoritative server” |
| Internationalisation | Lacking | Supported |
| Access control | None | “secure access”, “differentiated access” |
| gTLD requirement | “no longer required” since 28 January 2025, except .com, .name and .post | Required, under the gTLD RDAP Profile |
The timeline is longer than most people assume. ICANN’s security committee advised finding a WHOIS replacement in September 2011, the RFCs were finalised in March 2015, and gTLD registries and registrars had to run an RDAP service by 26 August 2019.
How to do an RDAP lookup: three ways
ICANN stresses that “RDAP is a protocol, not a website”, used through “a command line utility, lookup software, or third-party website”. In practice that means three routes.
1. ICANN Lookup in a browser
Go to lookup.icann.org and type the domain into the box labelled “Enter a domain name or an Internet number resource (IP Network or ASN)”. ICANN says the results “come directly from registry operators and/or registrars in real-time” and that it does not store them. If a name is not available in RDAP, the query falls back to the registry’s WHOIS. The old whois.icann.org now redirects here. ICANN also maintains an open-source command-line client on GitHub for scripted lookups.
2. curl against a bootstrap service
RDAP.ORG is an independent redirect service, run by an ICANN employee “in my own time and at my own cost”, not by ICANN. It forwards a request to the right registry:
curl -Ls https://rdap.org/domain/example.com | jq .On 19 October 2026 that returned a 302 redirect to https://rdap.verisign.com/com/v1/domain/example.com. It allows “a maximum of 10 requests in 10 seconds”. To skip the middleman, IANA’s bootstrap file at https://data.iana.org/rdap/dns.json maps each TLD to its registry’s base URL: https://rdap.verisign.com/com/v1/ for .com, https://rdap.publicinterestregistry.org/rdap/ for .org.
3. Your registrar’s own tool
Registrars run RDAP servers too. Cloudflare’s, for example, is at https://rdap.cloudflare.com/.
Reading an RDAP response
Here is Verisign’s response for example.com, fetched 19 October 2026 and trimmed to the useful fields:
"objectClassName": "domain",
"ldhName": "EXAMPLE.COM",
"status": ["client delete prohibited", "client transfer prohibited", "client update prohibited"],
"events": [
{"eventAction": "registration", "eventDate": "1995-08-14T04:00:00Z"},
{"eventAction": "expiration", "eventDate": "2027-08-13T04:00:00Z"},
{"eventAction": "last changed", "eventDate": "2026-08-14T08:01:43Z"}
],
"nameservers": [{"ldhName": "ELLIOTT.NS.CLOUDFLARE.COM"}, {"ldhName": "HERA.NS.CLOUDFLARE.COM"}]The registrar entity in the full response is “RESERVED-Internet Assigned Numbers Authority”, because example.com is a reserved name. A real domain shows its registrar there.
| RDAP field | What it tells you |
|---|---|
events / registration | Creation date |
events / expiration | Expiry date |
status | EPP status codes such as transfer locks |
nameservers | Where the domain’s DNS is hosted |
entities (registrar) | Which registrar holds the registration |
| Registrant contact | Usually “REDACTED” for gTLDs |
The status values are written with spaces in RDAP and in camel case in WHOIS; our guide to domain status codes explains which are normal locks and which signal trouble. The response also carries a “last update of RDAP database” event, which changes on every query and means nothing about the domain.
What an RDAP lookup will not show you
The owner. Under ICANN’s Registration Data Policy, gTLD registrant name, street, postal code and phone are replaced with “REDACTED”, and the email with a relay address or web form. ICANN Lookup says to expect “a remark and/or redacted label” in those fields. Nonpublic data can be requested through ICANN’s Registration Data Request Service, but that is meant for groups such as law enforcement and intellectual property professionals, not would-be buyers. Why the fields are blank is covered in domain privacy protection.
The past. ICANN describes RDAP as access to “current registration data”. Earlier owners and old records are a separate search; see domain ownership history.
Every extension. ICANN’s mandate covers gTLDs. In IANA’s bootstrap file published 30 September 2026, .de, .io and .us had no entry, so an RDAP query for those may return nothing useful. ICANN also notes “there may be variances across registrars and registry operators in what data is returned”.
When an RDAP lookup is worth running
Before buying a domain, it confirms the registrar, the creation date and whether the client locks a seller will need to lift are present. Before a transfer, it shows the status and expiry. After moving host, it confirms the nameservers changed. For an expired name, check the lifecycle status against our guide on when expired domains become available.
For more than one domain, the free Domain Age Checker reads the registry’s RDAP data for up to 20 domains and flags names that were dropped and re-registered. The Domain Expiry Checker shows when a domain expires and, if it has lapsed, whether it is in grace, redemption or pending delete.
A limitation: an RDAP response is a snapshot of what the registry or registrar returns at that moment. It cannot tell you why a status was set, who the private owner is, or what happened to the name before.
How the bootstrap finds the right server
The feature that makes an RDAP lookup work from anywhere is what ICANN calls “bootstrap”: “Instead of returning a result such as “not available,” a query will route to the authoritative server to return the relevant data.” With WHOIS you had to know which server to ask; with RDAP the client reads IANA’s bootstrap file, defined in RFC 9224, and goes straight to the registry that holds the record.
That file is maintained by IANA, and the list is only as complete as the TLD operators make it. IANA’s own page says anyone wanting to add a server should “contact the affected TLD’s administrators”. Usage is already large: ICANN estimated over 10 billion RDAP queries a month as of December 2024.
Frequently asked questions
Is RDAP the same as WHOIS?
It returns the same registration data in a different structure. ICANN: “The registration data is the same, but the structure of the response is different.”
Is WHOIS gone?
Not entirely. Since 28 January 2025, gTLD registries and registrars are no longer required to provide it, except for .com, .name and .post. Some still do.
Can an RDAP lookup tell me who owns a domain?
Usually not for gTLDs: the registrant’s name, street, postal code and phone are redacted. You can contact the owner through the relay email or web form the registrar publishes.
Is there a free RDAP lookup tool?
Yes. ICANN Lookup at lookup.icann.org is free and runs in the browser, and ICANN also publishes an open-source command-line client.
The takeaway Use RDAP for registrar, dates, locks and nameservers: it is structured, it finds the right server, and for gTLDs it is the protocol registrars must support. Do not expect it to name the owner or cover every country-code extension.
