From WHOIS to RDAP: What changes for domain name holders?

When you register a domain name, some information about the Registrant, the Registrar, and the DNS servers is made public. It is, in a way, the identity card of a domain name: the Whois. To consult a Whois, you can use online tools on dedicated websites, Registry sites, or Registrar websites. For example, the ICANN Whois, or the Netim Whois.

Historically, it was the Whois protocol that made this data accessible. The Whois protocol had long been the reference tool to obtain information about a domain name and its registrant. However, this protocol was created in the 1980s and today showed several signs of aging.

To remedy this, the ICANN (Internet Corporation for Assigned Names and Numbers) introduced a new protocol: RDAP (Registration Data Access Protocol). More modern, this protocol has replaced Whois. But what does this change mean for the user?

Why was Whois no longer suitable today?

Created in 1982, Whois is a simple tool. A bit like a directory, you type a domain name and get back a block of information: registration date, Registrar, holder contact details…

But the Whois protocol had several limitations:

• No standardised formats: each Registry chose what information to provide, usually in plain, unstructured text, which often made the results difficult to read.
• No access control or restrictions: everyone had access to the same information, without distinction between a regular user, an authority, or a Registrar.
• Not designed for internationalisation: the Whois protocol did not support non-Latin characters (Cyrillic, Arabic, Asian…), or modern Unicode encodings (accented letters). As a result, internationalised domain names (IDNs) were displayed in an ACE (ASCII Compatible Encoding) format, always starting with “xn--“. For example: nétim.com would appear as xn--ntim-bpa.com. Read our article on IDNs to learn more.
• Obsolete protocol: Whois relied on access via TCP (port 43), without encryption or a modern API. Its results were therefore not easily integrable into web applications.
• No routing to the correct server: to obtain the right information, you had to know in advance which Whois server to query (Registry or Registrar).

This is why, in 2012, the IETF (Internet Engineering Task Force), with the support of ICANN, began working on the development of a modernised protocol: the RDAP (Registration Data Access Protocol).

In 2015, RDAP was standardised, and since 2017, deployment has been progressive among Registries and Registrars. Since January 28, 2025, RDAP has officially replaced Whois.

What are the advantages of the RDAP protocol?

The RDAP protocol was developed at the initiative of ICANN, mainly to overcome the technical limitations of Whois, and to enhance the security of registrants. Here are the main improvements brought by RDAP:

• • Clear, structured, and standardised format: responses are standardised with an orderly and logical display of data. They are provided in JSON format, making them readable by humans and usable by machines.
  • Differentiated access management: some sensitive information can be hidden from the general public but accessible to legitimate authorities. The identity of domain name registrants is thus better protected, while still allowing access to necessary information in case of disputes.x
  • International compatibility: native support for non-Latin characters (Cyrillic, Arabic, Chinese, accents…), for better readability of internationalised domain names (IDNs).
  • Modernised access protocol: RDAP works like a modern web API, with HTTP(s) / REST. Requests are encrypted and easily integrable into applications.
  • Automatic routing to the appropriate server: no need to know the Registry server before starting a query. RDAP automatically directs to the correct source of information.

So what does this change for users?

Overall, for all users, the switch to RDAP brings more clarity, more reliability, and more privacy.

Whether for a regular user or a business, the RDAP protocol does not change how searches are performed but simplifies the reading of the results.

From a technical perspective (for developers), the change lies in how data is accessed and used: the process is simplified thanks to REST API functionality.

To illustrate our points, below is a comparison of a Whois query and an RDAP query:

In summary, RDAP is the modern, standardised, and secure version of Whois. It is designed to be usable by both humans and machines, and most importantly, to meet current privacy requirements.

Note: Although the Whois data access protocol has been replaced by the RDAP protocol, the term “Whois” is still commonly used to refer to domain search tools.

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