CIDR Summarize / Aggregate
Merge or dedupe a CIDR list. Fail-fast on the first invalid line. Same family only.
Developer notes
One CIDR per line; # comments skipped. Fail-fast with line number. No mixed family. Never invents gap coverage.
Options
- Merge overlaps
- true = minimal covering merge; false = exact-string dedupe without adjacent merge.
- Output sort
- ascending = lexical CIDR sort; none = compute / first-occurrence order.
When teams pick this route
Shrink an allowlist. Dedupe an ACL export.
Worked examples
Nested merge
Before
After
Adjacent /25 → /24
Before
After
Related networking tools
For a start–end range, use ip-range-to-cidr. Back to the networking tools hub.
CIDR summarize FAQ
Merge & dedupe
When should I use the number-base converter instead?
To convert an integer between bases 2–36 (hex of a number, binary of a value), use number-base-converter. Networking tools compute subnets and CIDRs, not general base conversion.
Are IP addresses uploaded?
No. All math runs locally in your browser. Nothing is uploaded to FastMinify.
What is the size limit?
64 KiB (UTF-8) for the combined input fields of each tool.
Networking / IP
CIDR, subnets, and IPv4/IPv6 helpers — in your browser.
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