RDAP explained

WHOIS is a 1980s protocol: connect to port 43, send a domain name, get back free-form text. Every registry formats that text differently, there is no way to say who is asking, and there is no consistent way to mark data as redacted. The Registration Data Access Protocol (RDAP) fixes all three.

What RDAP changes

• Structured data. Answers are JSON with defined field names: events for dates, entities for registrar and contacts, nameservers, status, secureDNS. A tool can read every registry the same way.
• Discovery. IANA publishes a bootstrap file mapping each top-level domain to its RDAP server, so a client always knows where to ask.
• Redaction that says so. RFC 9537 lets a registry state that a field has been withheld and why, instead of silently omitting it.
• Access control. Registries can offer authenticated access with more data to parties with a lawful need, over HTTPS.

The .uk switch-off

Nominet has announced that its WHOIS service will cease on 9 February 2027. After that date, port-43 lookups for .uk domains will not answer; RDAP at rdap.nominet.uk is the only public interface. Generic top-level domains (.com, .org and the rest) are already required to offer RDAP and many are retiring WHOIS too.

What you see on whois.me.uk

The Registry facet is built from the RDAP document. The Source data drawer shows the raw JSON together with any notices the registry attaches, which usually contain its terms of use. Where a registry still runs WHOIS we fetch that too and show the text for comparison.

For developers

An RDAP domain lookup is a single HTTPS request: GET https://rdap.nominet.uk/uk/domain/example.co.uk with Accept: application/rdap+json. A 404 means the name is not registered; a 200 carries the record. Respect the registry's rate limits and cache results; the JSON export on our permalinks gives you the normalised form without writing a parser.