About RDAP.nu

What is RDAP?

RDAP (Registration Data Access Protocol) is the modern, standardized replacement for the legacy WHOIS protocol. Developed by the IETF, RDAP provides structured, machine-readable registration data for domains, IP addresses, and autonomous system numbers (ASNs).

Why RDAP over WHOIS?

RDAP offers several advantages over the aging WHOIS protocol:

• Structured data: JSON responses instead of inconsistent plain text
• Standardized: Same format across all registries worldwide
• Internationalization: Proper Unicode and language support
• Secure: HTTPS transport with authentication support
• Extensible: Registries can add custom fields while maintaining compatibility
• Differentiated access: Support for varying access levels based on user authentication

What This Tool Does

RDAP.nu queries both RDAP and traditional WHOIS sources, normalizes the data into a consistent format, and lets you compare the results side by side. This helps you:

• See what data is available from each protocol
• Verify registration information across sources
• Understand the transition from WHOIS to RDAP
• Access registration data in a clean, readable format

Supported Lookups

• Domains: .com, .net, .org, and most TLDs with RDAP support
• IP Addresses: IPv4 and IPv6 addresses from all RIRs
• ASNs: Autonomous System Numbers from ARIN, RIPE, APNIC, LACNIC, and AFRINIC

Data Sources

This tool queries authoritative sources based on the IANA bootstrap files, which map resources to their responsible registries. For WHOIS, we use the standard WHOIS protocol to query each registry's WHOIS server directly.

Regional Internet Registries (RIRs):

• ARIN - American Registry for Internet Numbers
• RIPE NCC - Europe, Middle East, Central Asia
• APNIC - Asia-Pacific region
• LACNIC - Latin America and Caribbean
• AFRINIC - Africa