Expand, compress, and range IPv6
IPv6 addresses are long, and the notation allows shortcuts — dropping leading zeros and collapsing a run of zero groups with a double colon. That makes the same address look different in compressed and expanded forms. This calculator converts between them and works out the range for a prefix, which helps when reading configs or planning IPv6 addressing.
How to use it
- Enter an IPv6 address or prefix.
- See the expanded and compressed forms, and the range.
- Copy the form you need.
Where it helps
- Reading an address that was written in compressed form.
- Confirming two notations refer to the same address.
- Planning IPv6 prefixes and ranges.
Questions people ask
What does the double colon mean? It stands in for one run of consecutive zero groups, and can appear only once in an address so it's unambiguous.
Is my input stored? No — the calculation runs in your browser.