// Tool
IPv6 Tools
Expand, compress, and inspect any IPv6 address. Detect address type, calculate the network and prefix range, and see the full binary breakdown.
Frequently Asked Questions
What is the difference between compressed and expanded IPv6?
Expanded form shows all 32 hex digits in 8 groups; compressed form drops leading zeros and collapses one run of all-zero groups to ::. For example
2001:0db8:0000:0000:0000:0000:0000:0001 compresses to 2001:db8::1.Can :: appear more than once in an address?
No. The :: shorthand may be used only once, because more than one occurrence would be ambiguous about how many zero groups each represents.
Why is the IPv6 host portion usually /64?
A
/64 is the standard subnet size because Stateless Address Autoconfiguration (SLAAC) uses the lower 64 bits for the interface identifier. Subnets smaller than /64 break SLAAC.