Use this network utility to parse, normalize, convert, or derive IPv4, IPv6, subnet, reverse-DNS, or MAC addressing information under a stated prefix convention.

Netmask

Dotted-decimal netmask with contiguous set bits.

Convert a dotted-decimal IPv4 netmask into its CIDR prefix length. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Prefix

Prefix length in bits, 0 to 32.

• Syntax and arithmetic validity do not establish reachability, ownership, routing, DNS, privacy, or authorization. IPv4 special-use ranges, IPv6 scopes and compression, prefix boundaries, mapped forms, and host-count conventions require explicit handling.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Validate against current IANA registries and the target platform, test boundary prefixes, and use live network tools only with appropriate authorization.

• Prefix to Netmask

  Convert an IPv4 CIDR prefix length into a dotted-decimal netmask.

• IPv4 to Integer

  Convert a dotted-decimal IPv4 address into its 32-bit integer form.

• Integer to IPv4

  Convert an unsigned 32-bit integer into dotted-decimal IPv4 form.