Tool
Free RDAP & WHOIS Lookup Tool
Look up domain registration, IP address allocation, and ASN holder information using RDAP — the modern, structured replacement for WHOIS.
RDAP Viewer
RDAP-Informationen für Domains, IPs und ASNs
RDAP vs WHOIS: What's the Difference?
WHOIS has been the standard way to look up domain registration data since the 1980s. However, it returns unstructured text that varies wildly between registrars, making automated parsing unreliable. RDAP (Registration Data Access Protocol) was developed by the IETF as a modern replacement. It returns standardized JSON over HTTPS, supports internationalized domain names and Unicode contact data, and provides built-in mechanisms for differentiating access levels — critical for GDPR compliance.
How to Look Up Domain Registration Information
Select your query type (Domain, IP, or ASN), enter the value, and click Lookup. For domains, enter the full domain name (e.g., example.com). For IP addresses, enter an IPv4 or IPv6 address. For ASNs, enter just the number (e.g., 13335 for Cloudflare). The tool validates your input before sending the query to prevent malformed requests.
Understanding RDAP Response Data
An RDAP response includes the entity handle (unique identifier), registration and expiration dates, current status codes (like active, clientTransferProhibited), nameserver information, and contact entities (registrant, admin, tech) where published. Status codes indicate whether a domain can be transferred, renewed, or deleted. For IP lookups, you'll see the allocated CIDR range, the Regional Internet Registry (RIR), and abuse contact information.
Privacy & Data Handling
All queries go directly from your browser to the public RDAP bootstrap servers at rdap.org. No data is proxied through or stored by NetScopeKit. The tool is purely client-side.
Frequently Asked Questions
- What is RDAP?
- RDAP (Registration Data Access Protocol) is the modern, standardized replacement for WHOIS. It returns structured JSON data about domain registrations, IP address allocations, and Autonomous System Numbers (ASNs), making it easier to parse and more reliable than legacy WHOIS.
- What is the difference between RDAP and WHOIS?
- WHOIS returns unstructured plain text that varies between registrars, while RDAP returns standardized JSON data. RDAP also supports HTTPS encryption, better internationalization (Unicode), and standardized access controls for privacy compliance.
- What information does an RDAP lookup return?
- For domains: registrar, registration and expiration dates, nameservers, status codes, and (if published) contact details. For IP addresses: the allocated network range, organization, and abuse contact. For ASNs: the AS number, holder, and registration details.
- Can I look up any domain?
- You can look up most domains, IP addresses, and ASNs. Some registries may rate-limit queries or restrict certain data for privacy reasons (especially under GDPR). The availability of contact details varies by registry and registrar.
- Is my query data stored?
- No. RDAP queries are sent directly from your browser to the rdap.org bootstrap service. No data passes through or is logged by NetScopeKit.