Convert an IP address between CIDR, range and integer

Move IPv4 values between dotted notation, unsigned integers, CIDR ranges, and exact CIDR cover sets.

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ToolNetwork Address Converter
Input
Output
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How it works

Four octets pack into one unsigned 32-bit value and unpack through bit shifts. Prefix masks find CIDR endpoints, while range conversion repeatedly takes the largest aligned power-of-two block that stays inside the requested interval.

  • The scope is IPv4, so values stop at 2³²−1 and prefix lengths at 32.
  • If start exceeds end, the endpoints are swapped before covering the interval.

Worked example

Cover one IPv4 /24 exactly
Input
											192.168.1.0 - 192.168.1.255
Output
												192.168.1.0/24
256 addresses

When to use this

Firewall inventories expand prefixes, databases store IPv4 as integers, and routing lists cover exact contiguous ranges.

Edge cases

  • IPv6 cannot fit this 32-bit representation.
  • An unaligned interval can require several prefixes even when its address count is a power of two.
  • An integer beginning with zero is interpreted as octal, which can surprise callers expecting decimal.

References