CIDR Range Expander
Expand a CIDR block into individual addresses, or compress a range into CIDR blocks.
Expand CIDR to addresses
List every address in a block
Range to minimal CIDR
Convert an IP range into the fewest CIDR blocks
About the CIDR Range Expander
List every address contained in a CIDR block, or take an arbitrary start/end IP range and compute the minimal set of CIDR blocks that exactly covers it — useful for firewall rules and allow-lists.
Examples
Range to CIDR
10.0.0.5 - 10.0.0.20Output
10.0.0.5/32, 10.0.0.6/31, ...Related tools
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Frequently asked questions
Read more
- Subnetting and CIDR explained without the headache
What a /24 actually means, how to calculate usable hosts, and how to read a CIDR range without a lookup table.
Version 1.0.0 · Updated 2026-08-06 · Runs entirely in your browser