RDAP Lookup for Domain Registration Data
OpenRDAP is a fast RDAP lookup tool for public domain registration data. Enter a domain name to run an RDAP search against the authoritative registry or registrar endpoint and review structured registration details in your browser.
RDAP stands for Registration Data Access Protocol. It is the modern protocol for domain, nameserver, and entity registration records. OpenRDAP helps developers, security teams, researchers, brand owners, and site operators inspect registrar information, domain status, nameservers, registration events, notices, and raw RDAP JSON without creating an account or sending the query through an OpenRDAP backend proxy.
What is RDAP?
RDAP stands for Registration Data Access Protocol. It is the modern standard for retrieving public internet registration data over HTTPS in structured JSON. RDAP was created to replace legacy WHOIS with a more consistent protocol for domain, nameserver, and entity registration records.
Because RDAP responses use predictable fields, an RDAP lookup is easier
to parse, compare, automate, and audit than legacy WHOIS output.
OpenRDAP focuses on domain RDAP lookup, which means it queries
/domain/{domain} endpoints for domain registration records.
RDAP vs WHOIS
WHOIS search usually returns unstructured text that varies by registry. RDAP search returns machine-readable JSON with clearer fields for domain status, events, entities, notices, links, and nameservers. For technical users, RDAP is usually better for automation, diagnostics, and repeatable domain registration checks.
OpenRDAP uses RDAP only. It discovers the correct RDAP server with the IANA RDAP DNS bootstrap registry, then performs the RDAP lookup directly from your browser.
Every search opens a direct domain lookup URL such as
/domain/example.com. The result page remains fully
client-side rendered: the browser loads OpenRDAP, fetches public RDAP
data, and displays domain registration lookup results without a
server-side OpenRDAP proxy. If your search intent is specifically WHOIS,
use the dedicated WHOIS domain lookup page.
| Need | Legacy WHOIS | RDAP search in OpenRDAP |
|---|---|---|
| Domain registration lookup | Legacy plain-text registration output. | Structured public registration data in JSON. |
| Registrar and nameserver review | Often available, but formatting varies. | Displayed as readable summary fields when published. |
| Developer automation | Requires parsing inconsistent text. | Uses predictable RDAP objects, events, links, and notices. |
How the OpenRDAP Search Tool Works
- Normalize the domain name entered in the RDAP search field.
- Extract the top-level domain, such as
.com. - Load the IANA RDAP DNS bootstrap registry.
- Match the TLD to an authoritative RDAP base URL.
- Query
/domain/{domain}from your browser. - Display an RDAP lookup summary and the raw JSON response.
What an RDAP Lookup Can Show
Public RDAP lookup results vary by registry, registrar, and domain. A response may include the domain handle, registrar-related entities, domain status codes, nameservers, registration dates, expiration dates, last-changed events, public notices, terms of use, and links supplied by the authoritative RDAP server.
RDAP is public registration data, not private account data. Many RDAP records redact personal contact details because of privacy law, registry policy, or registrar policy. Redacted RDAP fields are normal and do not mean that the RDAP search failed.
| Field | Common use |
|---|---|
| Registrar | Find which registrar manages the public domain record. |
| Nameservers | Review DNS delegation for the domain. |
| Status codes | Check locks, holds, and other registry status values. |
| Events | Review registration, expiration, and last-changed dates. |
| Raw JSON | Copy or inspect the authoritative RDAP response. |
Common Use Cases
Security investigations
Security teams use RDAP lookup results to review suspicious domains, registrar information, nameserver patterns, status codes, and public registration timelines.
Domain ownership research
Domain buyers, brand teams, and site owners use WHOIS-style domain lookup to understand registrar details and public registration signals before contacting a registrar or taking further action. For that search intent, OpenRDAP also provides a dedicated WHOIS lookup page.
Developer workflows
Developers use RDAP because structured JSON is easier to compare, document, and automate than legacy WHOIS text. OpenRDAP keeps the raw response available for technical review.
Common RDAP Search Response Codes
- 200 — RDAP record found.
- 404 — No RDAP record from that endpoint; not proof of availability.
- 429 — Rate limited by the RDAP server.
- 5xx — RDAP server error.
- Browser network/CORS error — The server may not allow browser-origin access.
FAQ
Is OpenRDAP a WHOIS lookup tool?
OpenRDAP helps you look up public domain registration data like a WHOIS lookup, but it uses RDAP instead of legacy WHOIS. RDAP is the modern protocol for structured domain registration data.
What is an RDAP lookup?
An RDAP lookup is a search against an authoritative Registration Data Access Protocol server for public domain registration data. It can return registrar information, domain status, nameservers, events, notices, and raw JSON when the RDAP server provides those fields.
Is RDAP search the same as WHOIS search?
No. WHOIS search commonly returns plain text, while RDAP search returns structured JSON over HTTPS. RDAP is better suited for modern applications, API workflows, and automated domain registration checks.
Can I open a direct domain lookup URL?
Yes. URLs like /domain/example.com load a client-side
RDAP search page and show WHOIS-style domain lookup results after the
browser fetches public registration data.
What RDAP search intent does OpenRDAP support?
The homepage is designed for RDAP lookup, RDAP search, domain RDAP lookup, public domain registration lookup, registrar lookup, nameserver lookup, domain status lookup, and raw RDAP JSON review. Users looking for WHOIS search can use the WHOIS domain lookup page.
Is this a domain availability checker?
No. RDAP lookup and domain availability checking are different. A missing RDAP record does not guarantee that a domain is available to register. Confirm commercial availability with an accredited registrar.
Why direct browser queries?
Direct browser queries avoid routing every RDAP lookup through OpenRDAP infrastructure. This keeps the RDAP search tool lightweight, reduces centralized rate-limit risk, and lets your browser talk to IANA and the authoritative RDAP server directly.
Does OpenRDAP store my searches?
OpenRDAP v1 does not proxy RDAP lookups, require an account, or store a server-side lookup history. Queries go from your browser to IANA and the relevant public RDAP servers. Read the privacy note.
Privacy note
Your RDAP search may be visible to IANA during bootstrap discovery, the authoritative RDAP server that answers the lookup, and your network provider. OpenRDAP v1 does not proxy RDAP requests through its own backend.