RDAP vs WHOIS: what is the difference?
RDAP is the modern way to look up who runs a domain, when it expires and what its status is: it returns structured JSON over HTTPS, where WHOIS returned plain text on its own port. ICANN made it the definitive source for generic domains as of 28 January 2025.
| WHOIS | RDAP | |
|---|---|---|
| How you ask | A text line sent to a server on TCP port 43 (RFC 3912). | An HTTP request to a web address such as …/domain/example.com (RFC 9082). |
| What you get back | Human-readable text, with no way to say which character set it uses (RFC 3912). | JSON with named fields, such as events and status (RFC 9083). |
| Finding the right server | RFC 3912 does not say how a client chooses the server. | IANA publishes a list of servers by ending (RFC 9224). |
| Internationalization | ICANN lists it as something RDAP adds. | Supported, per ICANN. |
| Access to data | ICANN lists secure access and differentiated access as things RDAP adds. | Secure access over HTTPS and different levels of access, per ICANN. |
| Status of the protocol for generic domains | Retired from 28 January 2025, per ICANN. | The definitive source from 28 January 2025, per ICANN. |
Source: ICANN: Launching RDAP; sunsetting WHOIS (27 January 2025); RFC 3912: WHOIS protocol specification; RFC 9082: Registration Data Access Protocol queries; RFC 9083: JSON responses for RDAP; RFC 9224: Finding the authoritative RDAP service, opened on .
What an RDAP answer looks like
This is a trimmed copy of what the .com registry returned for example.com on Oct 11, 2026. The full answer also lists the registrar and the name servers. A program, or this page, can pick out the “expiration” event by its name, which is easier for a program than picking a date out of free text.
The status values are written the RDAP way: lower case with spaces, as RFC 8056 maps them from the EPP names.
{
"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"
}
]
}What is RDAP?
RDAP stands for Registration Data Access Protocol. It lets a program ask a registry for a domain’s registration data over the web and get an answer in JSON, a format that software can read without guessing. The IETF developed it, RFC 9082 defines the web addresses it uses, and RFC 9083 defines the shape of the answers.
What is WHOIS?
WHOIS is the older lookup protocol. Under RFC 3912, from September 2004, a WHOIS server listens on TCP port 43, the client sends a line of text and the server replies with text. The text is meant for people to read, and the RFC notes that the protocol has no way to say which character set it uses, so a program has to work out what it is looking at.
Why did RDAP replace WHOIS?
ICANN lists four advantages of RDAP: support for internationalization, secure access to data, authoritative service discovery, and the ability to give different people different levels of access to registration data. Service discovery is the part this site relies on: IANA publishes which server answers for each ending (RFC 9224), so a client knows whom to ask.
When did WHOIS end?
ICANN announced on 27 January 2025 that as of 28 January 2025 RDAP is the definitive source for generic top-level domain registration information, replacing the retired WHOIS services. That announcement covers generic domains such as .com and .org. It does not address country-code domains, and we have not read their registries’ policies, so we do not say what they do.
How does this site use RDAP?
When you press the button, your browser downloads IANA’s list of registry servers, finds the one for your ending and asks it for the record. The answer is checked, then shown. Our servers are not involved. It only works because the registries we tested allow web pages to read their answers; where one does not, the page says so.
Questions about rdap vs whois
Is WHOIS still available?
For generic domains ICANN describes the WHOIS services as retired from 28 January 2025, in favour of RDAP. Some registries and registrars may still run a WHOIS service of their own, which we have not surveyed, so treat any single WHOIS server as optional.
Is RDAP data the same as WHOIS data?
We did not find a statement of that in ICANN’s announcement, so we do not claim it. What the announcement does say is that RDAP can give differentiated access, so a record can show less to the public than an old WHOIS answer did.
Is RDAP faster or more private than WHOIS?
ICANN names “secure access to data” as an advantage, because RDAP runs over HTTPS. Speed depends on the server, and we have not measured it. Privacy depends on what the registry publishes: this site shows only dates, status codes and the registrar’s name.
Why does a domain ending have no RDAP server?
IANA’s file of 2026-09-30 lists servers for 1,203 endings. Many country codes are not in it, including .io, .co, .me, .us, .de and .eu, which means the file gives a client no server to call for them. For these endings, each official registry provides an alternative source—such as an official web search tool and a port-43 WHOIS server—which this site catalogs from IANA’s Root Zone Database.
What is ICANN Lookup?
ICANN’s own RDAP-based lookup service, at lookup.icann.org. ICANN encourages people to use it, and it is a good second opinion when a registry’s server cannot be reached from a browser.
What is rdap.org?
A public redirector that sends a query to the right registry. Its own page says it limits clients to 10 requests in 10 seconds and recommends using the IANA bootstrap files directly for high volume. This site goes straight to the registry and does not use it.
Related pages
More about expiring domains.
Domain expiration checker
Type a domain and see when it expires, read from the registry.Domain status codes
What clientTransferProhibited, redemptionPeriod and the rest mean.Domain expiration timeline
What happens after a domain expires, step by step.Days until expiry calculator
Days left for any date, with calendar reminders.
Sources and limits
- ICANN: Launching RDAP; sunsetting WHOIS (27 January 2025)
As of 28 January 2025 RDAP is the definitive source for gTLD registration data, replacing the retired WHOIS services; its advantages (internationalization, secure access, authoritative service discovery, differentiated access); developed by the IETF; ICANN Lookup at lookup.icann.org.
ICANN. Opened on .
- RFC 3912: WHOIS protocol specification
WHOIS on the wire: a server listens on TCP port 43, the client sends a text request and the server replies with text (September 2004).
IETF. Opened on .
- RFC 9082: Registration Data Access Protocol queries
The URL pattern for a domain lookup, domain/<name>, with internationalized names written in their A-label (ASCII) form.
IETF. Opened on .
- RFC 9083: JSON responses for RDAP
The shape of a domain answer, the event names (the "expiration" event is the date the object is removed from the registry unless renewed) and the registered status values.
IETF. Opened on .
- RFC 9224: Finding the authoritative RDAP service
How a client picks the server: match label by label from the right with the longest match winning, prefer https, base URLs end in a slash, and clients should not fetch the bootstrap file on every request but cache it.
IETF. Opened on .
- RFC 8056: EPP status mapping to RDAP
How an EPP status such as clientTransferProhibited is written in RDAP: lower case with spaces ("client transfer prohibited"), with "ok" written as "active".
IETF. Opened on .
- RDAP.org: about the service
The public redirector for RDAP. It states no terms of use beyond blocking abuse, limits clients to 10 requests in 10 seconds (429 when exceeded) and says to use the IANA bootstrap files directly for high volume. This site does not call it.
RDAP.org. Opened on .
Not confirmed: The announcement does not state whether the data in RDAP is the same as in the old WHOIS, and we did not survey which registries still run a WHOIS server. We state neither.
This is information, not advice. A registry or registrar can change a record at any time. Before you rely on a date, confirm it with your registrar, who is the only one that can renew the domain.