IPv6 address type checker
Paste any IPv6 address to see its type, scope, and whether its interface ID is hardware-derived or randomized.
The five IPv6 address types at a glance
Every IPv6 address falls into one of five categories. Most devices carry several of these at once on a single interface, which is normal. Our IPv6 address types guide covers the full mechanics behind each row below.
| Type | Prefix | Routable | Purpose |
|---|---|---|---|
| Link-local | fe80::/10 | No, local segment only | Automatic on every interface, used for neighbor discovery |
| Global unicast | 2000::/3 | Yes, internet-wide | Public IPv6 address, the equivalent of a public IPv4 |
| Unique local | fc00::/7 | No, private only | IPv6’s version of RFC 1918 private ranges |
| Multicast | ff00::/8 | Scoped by group | One-to-many delivery, replaces IPv4 broadcast entirely |
| Loopback | ::1/128 | No, local device only | The equivalent of IPv4’s 127.0.0.1 |
Reading your interface ID
The last 64 bits of a link-local or global unicast address, the interface ID, get built one of two ways. EUI-64 derives it from your device’s MAC address, leaving an ff:fe marker in the middle. Privacy extensions, defined in RFC 8981, generate a random interface ID instead and rotate it roughly once a day. This tool checks for that marker and tells you which one you are looking at.
Frequently asked questions
Is this tool sending my address anywhere?
No. Every check runs in your browser. Nothing you type is sent to any server, logged, or stored.
Why does it say my interface ID is randomized instead of showing a MAC address?
Most modern operating systems use privacy extensions by default. Instead of deriving the address from your MAC, they generate a random interface ID and rotate it roughly once a day.
Can this tool check IPv4 addresses too?
No. This checker is IPv6-only. For IPv4, use our IP to binary converter, which also detects private, CGNAT, and loopback ranges.