IPv6 WHOIS Lookup
Look up any IPv6 address and see who it belongs to: the owning organisation, Regional Internet Registry, allocated range, origin ASN, abuse contact and reverse DNS. The tool runs entirely in your browser and queries the registries' official RDAP servers directly — nothing you type is sent to our server.
How the IPv6 Lookup Works
Enter Any IPv6 Address
Paste an address in any valid notation — fully expanded, compressed with a double colon, or IPv4-mapped. The tool validates it instantly and tells you exactly what is wrong if the format is off.
Queried at the Source
Your browser picks the correct Regional Internet Registry from IANA's official delegation table and asks its RDAP server directly. No middleman database that might be stale or incomplete.
Instant Address Math
The compressed form, the fully expanded form and the ip6.arpa reverse-DNS name are computed locally the moment you hit Lookup — they appear even with no network connection at all.
What Data Does an IPv6 WHOIS Lookup Provide?
Every public IPv6 address belongs to a block that some organisation registered with a Regional Internet Registry. That registration is public by design, and a WHOIS lookup surfaces all of it in one place:
Network Owner & Organisation
The name of the ISP, hosting provider, cloud platform or enterprise the block is allocated to, together with the network's registry handle and its official name.
Registry & Registration Dates
Which of the five Regional Internet Registries manages the block, when it was first registered, and when the record was last updated — useful for judging how established a network is.
ASN & Announced Prefix
The autonomous system number that actually announces the address in the global BGP routing table, plus the exact prefix being routed — the answer to 'who operates this network right now'.
Abuse Contact
The email address and phone number the owner publishes for abuse reports — the right place to send evidence of spam, scanning or attacks coming from the address.
Reverse DNS (PTR)
The hostname the address resolves back to via its ip6.arpa PTR record. A meaningful PTR often reveals the service behind an address — mail servers, VPN endpoints, CDN nodes.
Compressed & Expanded Forms
Both canonical spellings of the address, plus its reverse-DNS name — handy for firewall rules, DNS zone files and log correlation where notation must match exactly.
What Is an IPv6 Address?
IPv6 is the current version of the Internet Protocol, designed to replace IPv4 as the address space of the original internet ran out. An IPv6 address is 128 bits long, written as eight groups of four hexadecimal digits separated by colons. That length gives IPv6 roughly 340 undecillion addresses — 3.4×1038, against the 4.3 billion that 32-bit IPv4 can offer.
Because full addresses are long, two shortening rules exist: leading zeros inside a group can be dropped, and
the single longest run of all-zero groups can be replaced with a double colon. The documentation address
2001:0db8:0000:0000:0000:0000:0000:0001
therefore compresses to
2001:db8::1.
Both spellings name exactly the same address, which is why this tool always shows you both — logs, firewall
rules and allowlists frequently disagree about which form they use.
The first half of a typical address (up to 64 bits) identifies the network and is what registries allocate and BGP routes; the second half identifies the individual interface and is often generated automatically by the device itself. That structure is why a WHOIS lookup describes the network an address belongs to rather than the specific machine using it.
IPv6 vs IPv4: What Actually Changed
Vastly Larger Address Space
128-bit addresses instead of 32-bit. Every device, sensor and container can hold a globally unique address without rationing.
No NAT Required
With enough addresses for everyone, end-to-end connectivity returns — simplifying peer-to-peer applications, gaming and VoIP.
Simplified Header
The IPv6 header has a fixed length and fewer fields, letting routers make forwarding decisions faster than with IPv4's variable header.
Auto-Configuration (SLAAC)
Devices can configure their own addresses from router announcements — no DHCP server needed for basic connectivity.
IPsec Designed In
Packet-level authentication and encryption were part of the IPv6 specification from the start rather than being retrofitted.
Multicast & Anycast
Broadcast is gone; efficient multicast and anycast routing take its place, which is how modern DNS and CDN services stay fast.
Who Allocates IPv6 Addresses?
At the top of the hierarchy sits IANA, the Internet Assigned Numbers Authority, which hands out large IPv6 blocks to five Regional Internet Registries. Each RIR allocates space to ISPs and organisations in its region and publishes the registration data this tool reads. Since 2015 the registries have served that data over RDAP, the structured successor to the classic port-43 WHOIS protocol — same records, but delivered as JSON over HTTPS.
AFRINIC
Africa and parts of the Indian Ocean
APNIC
Asia-Pacific, including China, India, Japan and Australia
ARIN
United States, Canada and parts of the Caribbean
LACNIC
Latin America and the rest of the Caribbean
RIPE NCC
Europe, the Middle East and Central Asia
Special IPv6 Ranges
Not every IPv6 address has an owner. Several ranges are reserved by the protocol itself and will never appear in a registry database — if you look one up, "no registration found" is the correct answer:
::1 Loopback — the machine talking to itself, the IPv6 twin of 127.0.0.1
fe80::/10 Link-local — auto-configured on every interface, never routed beyond the local network segment
fc00::/7 Unique local — private addressing for internal networks, comparable to 10.0.0.0/8 in IPv4
ff00::/8 Multicast — one-to-many delivery; replaces IPv4 broadcast entirely
2001:db8::/32 Documentation — reserved for examples and manuals, never allocated to a real network
IPv6 Lookup — Frequently Asked Questions
What is an IPv6 WHOIS lookup?
An IPv6 WHOIS lookup queries the public registration databases maintained by the five Regional Internet Registries to find out who an IPv6 address block is allocated to. The result includes the network name, the owning organisation, the covering address range, registration and update dates, and an abuse contact for reporting misuse originating from that address.
What is RDAP, and how is it different from classic WHOIS?
RDAP (Registration Data Access Protocol) is the modern replacement for the 40-year-old WHOIS protocol. It serves the same registration data, but over HTTPS in structured JSON instead of free-form text, so results are machine-readable and consistent across registries. This tool queries the registries’ official RDAP servers directly from your browser.
Why does the result show an organisation instead of a person?
IPv6 addresses are allocated in large blocks to organisations — internet service providers, hosting companies, cloud platforms, universities — rather than to individuals. The registry records describe the organisation responsible for the block. Identifying the individual subscriber behind a single address is only possible for the ISP itself, normally under a legal request.
Can an IPv6 lookup reveal an exact physical location?
No. The registration country tells you where the owning organisation is based, and GeoIP databases such as MaxMind GeoLite2 estimate a city-level location from routing data — but neither pinpoints a street address or a person. Location estimates for IPv6 can be off by hundreds of kilometres, especially for mobile and tunnelled connections.
What is the difference between compressed and expanded IPv6 notation?
An expanded IPv6 address writes out all eight groups of four hexadecimal digits, for example 2001:0db8:0000:0000:0000:0000:0000:0001. The compressed form drops leading zeros and replaces the longest run of zero groups with a double colon, giving 2001:db8::1. Both spellings refer to exactly the same address; RFC 5952 defines the canonical compressed form.
What is a PTR record for an IPv6 address?
A PTR (pointer) record maps an IP address back to a hostname — the reverse of a normal DNS lookup. For IPv6, the address is written as 32 reversed hexadecimal digits under the ip6.arpa zone. Mail servers and logging systems often check PTR records, so a missing or mismatched one can affect email deliverability.
Why does my lookup say "no registration found"?
Some ranges are reserved and never allocated by a registry: documentation addresses (2001:db8::/32), link-local (fe80::/10), unique local (fc00::/7), loopback (::1) and multicast (ff00::/8). Lookups for those return no registration by design. A global address can also be unregistered if it sits in space that has not yet been allocated to any network.
Is this IPv6 lookup tool free and private?
Yes. The page is fully static and the lookups run in your browser, which talks directly to the official registry RDAP servers, the RIPEstat API and public DNS-over-HTTPS resolvers. The addresses you check are never sent to or stored on our server — there is no server-side code at all.
The IPv6 WHOIS lookup answers the practical question behind any unfamiliar address in your logs: who operates this network, and where do I report a problem? Because it queries the registries' own RDAP servers straight from your browser, the data is always as fresh as the registries themselves. Explore our other free tools as well — the BIP39 mnemonic generator, the private key generator and the seed phrase converter — or read more guides on the blog.