What changed: WHOIS stopped being mandatory
Since 28 January 2025, registries and registrars of generic domains (gTLDs) are no longer required to run WHOIS, either on port 43 or as a web page. RDAP became the primary source of registration data. The exceptions in the ICANN FAQ are .com, .name and .post. The phrase "WHOIS is dead" is wrong: it stopped being mandatory, and many operators kept it anyway.
Two things follow for a domain owner. First, the whois command still works for many zones, but the operator no longer has to maintain it, and one day it may stop answering. Second, scripts that parse WHOIS text will have to move to RDAP: the ICANN announcement of 27 January 2025 calls RDAP the "definitive source" for gTLD data.
Timeline: from decision to shutdown
The WHOIS shutdown was not sudden: ICANN approved the amendments on 30 April 2023, they took effect on 7 August 2023, and the shutdown date was set 18 months after that. The dates come from the ICANN page on the global amendments to the RA and RAA agreements.
| Date | Event |
|---|---|
| 30 April 2023 | The ICANN Board approved the global amendments |
| 7 August 2023 | The amendments took effect and the transition period (Ramp-Up) began |
| 3 February 2024 | The transition period ended |
| 28 January 2025 | WHOIS shutdown date (WHOIS Sunset Date) |
ICANN documents contain no separate "RDAP ratification" date: there is only the Board approval, the effective date and the WHOIS shutdown date.
RDAP and WHOIS: what is different
RDAP runs over HTTP and answers in JSON. WHOIS (RFC 3912, September 2004) is a query to port 43 and a free-text answer whose format differs from operator to operator. For a script the difference is critical: JSON parses unambiguously, while text needs regular expressions that break.
| Criterion | WHOIS | RDAP |
|---|---|---|
| Transport | port 43, RFC 3912 | HTTP request |
| Response format | free text | JSON, structure set by RFC 9083 |
| Query outcome | judged from the text | visible in the HTTP status code |
| Hidden data | no defined marking format | explicit markers, RFC 9537 |
| Finding the right server | you must know the address | IANA bootstrap file, RFC 9224 |
What RDAP gives a domain owner: a structured answer instead of text, HTTP status codes, the ability to return a different amount of data to different requesters (access control for personal data), explicit markers for hidden fields and links to the registrar.
Which RFCs stand behind it
RDAP is described by four IETF documents: the query format, the JSON response format, finding the right server and markers for hidden fields. The numbers matter not for an exam but for reading a response: fields such as rdapConformance and entities are defined in RFC 9083. WHOIS itself is described separately, in RFC 3912.
- RFC 9082 — query format (replaces RFC 7482).
- RFC 9083 — JSON responses (replaces RFC 7483).
- RFC 9224 — finding the right server, the bootstrap (replaces RFC 7484).
- RFC 9537 — markers for hidden fields in a response.
The design and history of WHOIS itself are covered in the article what is WHOIS.
How to look up domain data through RDAP
The simplest way is one curl request with the header Accept: application/rdap+json to rdap.org. It is a third-party redirector: it finds the right zone server itself and forwards your request. It is convenient but is not an official ICANN or IANA endpoint, so for important checks go to the zone server directly.
curl -sL -H 'Accept: application/rdap+json' https://rdap.org/domain/example.comThe answer is JSON with the fields ldhName (the domain name), status (statuses, for example a transfer prohibition), entities (related parties, including the registrar with the role registrar) and links.
If you do not want the command line, ICANN has a web tool at lookup.icann.org. Other ways to check without a console are collected in the article checking a domain online.
How to find the zone server: the IANA bootstrap
Each zone answers RDAP at its own address, and IANA publishes the list of addresses in the file https://data.iana.org/rdap/dns.json. The lookup method is described in RFC 9224. For the com zone the file lists a Verisign server, for ua it lists https://rdap.hostmaster.ua/. The file is updated, so do not hardcode the addresses in scripts.
curl -s https://data.iana.org/rdap/dns.json | jq -c '.services[] | select(.[0][] == "ua")'
curl -s https://rdap.hostmaster.ua/domain/hostmaster.uaHidden data and personal information
The owner's personal data is often hidden in a public response, and RDAP can show that explicitly: hidden fields are marked (RFC 9537 is devoted to this), and responses from the .ua zone carry the remark "Some of the data in this object has been removed." and the contact status private when the registrar has closed the data.
The practical conclusion for the owner: an empty or closed field does not mean the registrar has no data about you. In the .ua zone, full details about the registrant are requested from the registrar. How data is hidden for ordinary domains is described in the article WHOIS privacy protection.
National zones: what about ccTLDs
The ICANN requirement applies to generic domains, the gTLDs. For national zones (ccTLDs) the decision apparently stays with the zone operator: the ICANN FAQ speaks about gTLDs, and we found no direct quotation in official documents saying "RDAP is not mandatory for ccTLDs", so this is our conclusion.
An example is the .ua zone. Its administrator, Hostmaster LLC, launched RDAP (rdap.hostmaster.ua, RDAP regulation 1.0 dated 1 January 2025) and still kept WHOIS at whois.ua: you can test it with echo hostmaster.ua | nc whois.ua 43.
What a domain owner should do
Do not throw WHOIS out of your toolbox, but build new checks on RDAP. Start with an inventory: find everything that parses the text answer of WHOIS or waits for an open port 43, and move it to RDAP using the steps below. That way you see the problem early, not after a failure.
- Find scripts and monitors that parse WHOIS text or connect to port 43.
- Replace them with an RDAP request and JSON parsing; take the server address from the bootstrap, not from code.
- Look at the HTTP status code, not only the body: it shows how the server treated the request.
Bulk checks over a list of domains are covered in the article bulk WHOIS lookups through an API.
Frequently asked questions
Has WHOIS been switched off completely?
No. Since 28 January 2025 it is no longer mandatory for gTLDs, except .com, .name and .post, but many operators kept it, and the .ua zone keeps WHOIS at whois.ua. The accurate wording is this: RDAP became the primary source, WHOIS became optional.
How do I find out whether my zone has RDAP?
Find the zone in the IANA bootstrap file: if its entry lists a server address, the zone publishes data over RDAP.
Will RDAP show the owner of someone else's domain?
Not necessarily. Personal data is often hidden, and hidden fields are marked.
What should ZevsHost customers do?
Domains are registered and renewed in the billing system; check the public data of any domain with the methods from this article. If the data in RDAP or WHOIS differs from what billing shows, write to support.