RDAP, short for Registration Data Access Protocol, is the modern standard for reading public internet registration data. A practical RDAP lookup lets you enter a domain name, discover the correct public RDAP server, and inspect a structured response about the domain. For users who search for RDAP lookup, RDAP search, domain RDAP lookup, registrar lookup, nameserver lookup, domain status lookup, or public domain registration data, RDAP is the protocol designed for the job.
OpenRDAP focuses on domain registration records. It does not register domains, sell domains, or bypass registry policy. It helps you query public RDAP endpoints and read what those endpoints publish. The result can be useful for developers, security teams, brand protection teams, domain buyers, site owners, researchers, and anyone who needs a clearer alternative to legacy WHOIS text.
What is RDAP?
RDAP is a standardized protocol for registration data. It uses HTTPS, predictable URLs, structured JSON responses, typed links, notices, and status values. That structure is the big shift from older WHOIS output, which is commonly plain text and can vary from one registry to another.
In simple terms, RDAP answers questions like: what is the domain record, which nameservers are listed, which registrar or related entity is published, what status values are attached, which public events are available, and what notices or policy links came with the response. The exact answer depends on the registry, registrar, TLD, privacy policy, and the RDAP server behind the record.
How RDAP search works in OpenRDAP
A domain RDAP lookup starts with the domain you type. OpenRDAP
normalizes the input, identifies the top-level domain, checks the IANA
RDAP DNS bootstrap registry, chooses the authoritative RDAP base URL,
and queries the domain endpoint directly from your browser. A typical
request path looks like /domain/example.com on the RDAP
server selected for the TLD.
The IANA RDAP DNS bootstrap is important because there is no single
universal RDAP server for every domain. The bootstrap registry maps
TLDs to RDAP service URLs. For example, the service responsible for a
.com lookup is not necessarily the same service used for
another TLD. OpenRDAP uses that public bootstrap data so the lookup
can reach the right RDAP source without a hand-maintained registry
list.
What an RDAP lookup can show
RDAP responses vary, but useful domain registration records often include a domain object, a handle, the normalized domain name, status values, nameservers, registration events, related entities, public notices, and links. OpenRDAP displays a readable summary first and keeps the raw RDAP JSON available for technical review.
| RDAP field | What it helps you understand |
|---|---|
| Domain name and handle | Confirms the object returned by the authoritative RDAP service and the identifier used by the registry. |
| Registrar or entities | Shows published organization, registrar, abuse, or related entity data when the server includes it. |
| Status values | Helps identify transfer locks, update restrictions, holds, or other registry-level conditions. |
| Nameservers | Shows DNS delegation details that can help with operations, incident response, and ownership research. |
| Events | Can include registration, expiration, last changed, last update, or transfer-related timestamps. |
| Notices and links | Provide terms of use, redaction notes, related resources, and registry policy context. |
How to read RDAP results
Start with the domain name, registrar, status, nameservers, and events. These fields answer the most common RDAP search questions: does the result match the domain, who publishes or manages the public registration record, what DNS delegation is visible, and which dates are known. Then review notices and links, because they often explain why contact data is redacted or why certain fields are absent.
If you are a developer, inspect the raw JSON. RDAP uses arrays and nested objects, so the raw response can include details that are not shown in a compact visual summary. If you are a non-technical user, focus on the summary and treat missing data carefully. A field that is absent from an RDAP response is not the same as proof that the field does not exist anywhere.
RDAP lookup use cases
Security investigations
Security teams use RDAP lookup data while reviewing suspicious domains, phishing infrastructure, malware delivery hosts, nameserver patterns, registration timelines, and registrar information. RDAP does not decide whether a domain is malicious, but it gives analysts a structured source of public registration context.
Developer automation
Developers prefer RDAP because JSON is easier to parse than WHOIS text. A domain RDAP lookup can feed monitoring tools, internal audit scripts, domain inventory workflows, and research notebooks without brittle text scraping.
Domain ownership research
Site owners, domain buyers, and brand teams use RDAP search to review registrar details, nameservers, domain status, expiration events, and public notices before taking the next step with a registrar or legal process.
Important limitations
- RDAP is public registration data. It is not private account data.
- Personal contact details are often redacted by privacy law, registry policy, or registrar policy.
- A 404 or missing RDAP record does not prove that a domain is available to register.
- Some RDAP servers rate-limit requests or block browser-origin traffic with CORS rules.
- Different TLDs and registrars can publish different fields.
Use RDAP as a reliable public registration lookup method, not as a domain purchase decision by itself. If you need commercial availability, pricing, transfer rules, or ownership action, confirm with an accredited registrar.
RDAP response codes and errors
| Response | Meaning during RDAP search |
|---|---|
| 200 | The RDAP server returned a public record. |
| 404 | No record was returned by that endpoint. This is not proof that the domain can be registered. |
| 429 | The RDAP server rate-limited the request. |
| 5xx | The RDAP server had an error or was temporarily unavailable. |
| Browser network or CORS error | The endpoint may not allow direct browser requests, or the network request may have failed. |
RDAP guide FAQ
Is RDAP the same as WHOIS?
No. RDAP is the modern structured protocol for registration data, while WHOIS commonly refers to older plain-text lookup output. Many people still search for WHOIS because the term is familiar, but RDAP is better suited for modern web tools and automation.
Can RDAP find the domain owner?
RDAP can show public entity data if the registry or registrar publishes it. Personal owner contact details are often redacted. A domain owner lookup may therefore show registrar, organization, abuse, or policy information rather than private personal data.
Does OpenRDAP proxy searches?
OpenRDAP v1 runs lookups from your browser to IANA and the public RDAP server. There is no OpenRDAP backend proxy for the lookup path.