IP Range to CIDR — Exact Cover
Convert an inclusive start–end range into minimal exact CIDRs (IPv4 or IPv6).
Developer notes
start ≤ end is required. The cover is exact, with no overshoot. 64 KiB limit.
Options
- Output sort
- ascending = lexical CIDR sort; none = compute / first-occurrence order.
When teams pick this route
Turn a firewall range into a CIDR list. Check a non-aligned range.
Worked examples
Aligned /24
Before
After
Non-aligned
Before
After
Related networking tools
To aggregate CIDRs, use cidr-summarize. Back to the networking tools hub.
Range → CIDR FAQ
Exact cover
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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