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