IP Range to CIDR — Exact Cover
Convert an inclusive start–end range into minimal exact CIDRs (IPv4 or IPv6).
Developer notes
• start ≤ end required. • Exact cover — no overshoot. • 64 KiB limit.
Options
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: cidr-summarize. Hub: networking tools.
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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