CIDR range combiner
Combine overlapping or adjacent address ranges into the smallest equivalent CIDR list.
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Keep this page handy for next time.
- On a computer
- Press Ctrl + D, or Command + D on a Mac.
- On a phone or tablet
- Open your browser's menu or Share menu and look for Add Bookmark, Bookmark or Add to favourites.
A bookmark saves the page link. Save any tool results separately.
How to use this tool
- Combine overlapping or adjacent address ranges into the smallest equivalent CIDR list.
- Adjust the labelled settings, then run the tool. Copy the result or download it as a file.
Things to know
- Processing is local. Supplied code and network requests are never executed. Input and text settings are limited to 5 MiB combined; text settings alone are limited to 1 MiB.
- Enter CIDRs, individual IPs, or start-end ranges. IPv4 and IPv6 are handled separately.
- At most 10,000 input ranges, 256 characters per line and 128 bytes per endpoint. At most 50,000 output CIDRs. Output bytes are checked while CIDRs are generated.
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