Domain Tools

RDAP Lookup

Look up a domain's registration data using the modern RDAP protocol, with automatic WHOIS fallback.

Enter a domain to look up its registration data via RDAP - the modern, structured successor to WHOIS. Falls back to WHOIS automatically where RDAP isn't available.

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Registrar Lookup TLD Information Domain Age Checker Domain Availability Checker Domain Expiry Checker Reverse DNS Lookup WHOIS / RDAP Lookup IP to Domain Lookup

JustChecker tracks your domain's registration data automatically and alerts you before anything changes unexpectedly.

What Is RDAP?

RDAP (Registration Data Access Protocol) is the modern replacement for WHOIS. It returns registration data in a structured JSON format with standard fields. This tool queries the registry's RDAP server and falls back to WHOIS when RDAP is not available.

When to Use It

When you need clean, reliable registration data.
When a WHOIS server returns inconsistent text.

How to Use It

Enter the domain.
Review the registrar, dates, status and nameservers.

Understanding the Result

RDAP uses consistent field names and dates in ISO format, and it supports standard redaction of personal data.

Limitations

Most generic TLDs support RDAP, but some country-code registries still only offer WHOIS. For the classic view use the WHOIS / RDAP Lookup.

RDAP vs WHOIS

	WHOIS	RDAP
Format	Free text, different for every registry	Standard JSON
Dates	Many formats	ISO 8601
Transport	Plain text on port 43	HTTPS
Internationalisation	Limited	Unicode support
Access control	None	Supports different access levels

ICANN made RDAP the official source of registration data for generic top-level domains in 2025, and WHOIS is being phased out for them.

Example Query

Every RDAP server answers standard URLs, for example:

https://rdap.verisign.com/com/v1/domain/example.com

The response lists events (registration, expiration, last changed), status values, nameservers and entities such as the registrar. This tool finds the right server for each TLD using IANA's bootstrap registry.

When to Use It

Scripts and monitoring that need reliable, parseable dates.
Checking expiry dates across a portfolio of domains.
Confirming the registrar before a transfer.

For a quick summary, the WHOIS / RDAP Lookup shows the key fields; for the age alone, the Domain Age Checker.

Frequently Asked Questions

RDAP returns structured, standardized JSON data (rather than WHOIS's inconsistent, registry-by-registry free-text format), making results more reliable to parse and display accurately across every TLD.

This tool automatically falls back to traditional WHOIS in that case, so you still get a result - RDAP adoption varies by registry, though it has become the industry-standard direction for domain data going forward.

They generally draw from the same underlying registry data - RDAP's advantage is the standardized, structured format and often more precise data typing, not necessarily different underlying facts.

Yes - the same privacy protections and redaction policies (like GDPR-driven contact masking) generally apply to RDAP responses as they do to WHOIS, since both draw from the same registry data source.

The RDAP protocol itself does support IP address and autonomous system number lookups at the registry level - this specific tool is focused on domain name lookups.

ICANN has been actively driving registries and registrars toward RDAP as the standardized successor to WHOIS, offering internationalization support, structured data, and more consistent access policies across the entire domain industry.