Free IP tools

Calculators for the address maths that comes up constantly and is tedious to do by hand. No sign-up, no rate limits, and no request leaves your browser — the maths runs locally.

Addressing

Subnet calculatorNetwork and broadcast address, subnet mask, wildcard mask, usable host range and host count for any IPv4 block.
CIDR to IP rangeConvert a CIDR block to its first and last address, or collapse an arbitrary address range into the smallest set of CIDR blocks.

Conversion

IP address converterConvert an IPv4 address between dotted-quad, decimal, hexadecimal, binary and octal.
IPv6 expand & compressExpand an IPv6 address to its full 39-character form, or compress it to the canonical RFC 5952 short form.

Doing this for thousands of addresses?

These calculators run in your browser and never send us your input. When you need geolocation, ASN and network data for addresses in bulk, the API answers in one call — no key required to try it.

curl https://api.ipaddresstoday.com/api/v1/8.8.8.8

Read the API docs See pricing