CIDR Aggregator - Free Online Tool | PivaBox

Merge multiple CIDR ranges into minimal supernets — optimize firewall rules and routing tables

How to Use CIDR Aggregator

1. Paste or type one CIDR range per line in the input box, for example: 192.168.1.0/24, 10.0.0.0/16
2. Click Aggregate to merge overlapping and adjacent CIDR ranges into the minimal set of supernets
3. Review the aggregated result — each line shows the original CIDR range and total host count. Use Copy Result to copy all aggregated CIDRs at once

Frequently Asked Questions

What is CIDR aggregation?

CIDR aggregation (also called supernetting or route summarization) merges multiple smaller CIDR blocks into fewer larger ones. This reduces routing table size and simplifies firewall rules without changing the covered IP range.

Does CIDR Aggregator require network access?

No. All CIDR computation happens entirely in your browser using pure JavaScript. No data is ever sent to any server.

What does 'adjacent merge' mean?

Two CIDR ranges are adjacent when the end of one range plus one equals the start of another (e.g., 192.168.1.0/24 ends at 192.168.1.255, and 192.168.2.0/24 starts at 192.168.2.0). The aggregator merges adjacent ranges to produce the most compact representation possible.