CIDR Aggregation

Paste a list of IPv4 prefixes — adjacent and overlapping ranges are collapsed into the smallest common set of prefixes.

Notes

Exact, not rounded. Only adjacent and overlapping prefixes are merged. The result covers the same addresses as the input — nothing is invented.
Runs in your browser. The calculation happens entirely on your device. Nothing you type is transmitted, stored or analysed.
IPv4. The calculator works with IPv4 prefixes.