RDAP Lookup

What RDAP is

RDAP, the Registration Data Access Protocol, is the structured successor of WHOIS. Instead of free-form text over port 43, it serves JSON over HTTPS, with a defined schema for registrars, dates, statuses, name servers and, for IP addresses, networks and ranges. Registries for domain suffixes and the five regional internet registries operate the servers.

This tool finds the right server through the IANA bootstrap registry, so the query goes to the authoritative registry for that suffix or address block. It accepts a domain or a public IP address. For a host name such as www.example.com it falls back to the registered parent domain and tells you so.

How to read domain results

A domain answer lists the registrar, the registration, last-changed and expiration dates, the status values and the delegated name servers.

• Expiration date: when the registration lapses unless renewed. The tool flags dates that are close or already past.
• Statuses: EPP codes such as clientTransferProhibited, which locks transfers, or serverHold and pendingDelete, which signal serious problems. Some registries do not publish client locks through RDAP, so the registrar panel is authoritative.
• Name servers: the delegation recorded at the registry. Compare it with the NS records in the zone; a mismatch is a classic cause of intermittent resolution.
• Not found: the registry reports no such registration, which suggests the name is unregistered or the lookup used the wrong suffix.

How to read IP results

An IP answer shows the network name and handle, the start and end of the range, CIDR blocks, country, type and status, plus public roles such as the technical or abuse contact where the registry publishes them. It tells you which organisation holds the block, often the hosting provider rather than the customer using one address.

Why contact details are mostly missing

Since the introduction of privacy regulation, registries and registrars generally redact personal registrant data. You will usually see the registrar and technical status, not the registrant's name or email. This tool never tries to infer or reconstruct redacted details, and RDAP coverage varies: some suffixes publish richer data, a few publish no RDAP service at all and the lookup says so.

Common problems the data can reveal

• Domain close to expiry: a lapsed registration takes the website, mail and every DNS-based control offline and can expose the name to takeover.
• No transfer lock listed: if the registry reports statuses without a transfer-prohibited lock, check the registrar panel; enabling the lock makes unauthorised transfers harder.
• Unexpected name servers: delegation that does not match your DNS provider can indicate an unfinished migration.
• Hold statuses: server or client hold codes suspend resolution and need registrar action.

How to act on the findings safely

Prerequisites: access to the registrar account, with a monitored contact address and a valid payment method. Risk: transfers and name-server changes affect the whole domain, so make one change at a time. Rollback: write down the existing name servers and statuses before changing anything.

1. Renew the domain at the registrar and enable auto-renew.
2. Enable the registrar transfer lock, and consider a registry lock for critical domains if the registry offers it.
3. If the delegation is wrong, update the name servers at the registrar to those your DNS provider specifies, and keep the old ones active until caches expire.
4. Re-run the lookup after registrars publish the change; allow time because registry propagation is not instant.

Limits

Data is whatever the registry or registry operator publishes at that moment. A registration record says who registered a name or holds a network; it does not say who operates the service behind it. The tool contacts only public RDAP servers found through the bootstrap registry, over HTTPS, with capped response sizes. Failures are reported as unknown rather than as absence.

Frequently asked questions

Scope of this tool

• Registrant contact details are normally redacted by registries and are not inferred.

Written by DNS Tools editorial · Last updated 2026-10-09