WHOIS and RDAP explained
WHOIS is the decades-old protocol for looking up who holds an IP block, autonomous system or domain name. RDAP (Registration Data Access Protocol) is its modern, JSON-based replacement, now mandatory for gTLD registries and all five regional internet registries (ARIN, RIPE NCC, APNIC, LACNIC and AFRINIC).
Our lookup automatically finds the authoritative RDAP server for your query and summarises the most useful fields: holder, address range, country, registration dates, abuse contact and name servers.
Finding the abuse contact
To report spam, scanning or attacks from an IP address, use the abuse email shown in the results. It is the contact the network operator registered specifically for handling abuse reports.
よくある質問
Why is the registrant information redacted?
Since GDPR, most domain registries redact personal data. Organisation names and abuse contacts for IP networks are usually still public.
What can I look up?
IPv4 and IPv6 addresses or CIDR blocks, AS numbers (e.g. AS13335) and domain names.