IP Address Tool

Analyze any IPv4 or IPv6 address: validity, private or public, binary form, and CIDR subnet mask, network and broadcast details.

The address is parsed entirely in your browser. No lookup API, no network requests — nothing leaves your device.

Valid address
Category
Binary
Decimal
Subnet mask
Network
Broadcast

How It Works

Enter any IPv4 or IPv6 address and the tool decodes it entirely in your browser — no server, no lookup API, no network requests. It checks the format, classifies the address as private, loopback, link-local or public, and shows the address as a 32-bit binary value (for IPv4) or a single 32-bit decimal integer. With the optional prefix length (like /24), it computes the subnet mask, network address and broadcast address using plain bit arithmetic.

Validity rules
IPv4 must be exactly four decimal octets between 0 and 255, with no leading zeros. IPv6 must be eight groups of up to four hex digits, or the compressed form with one '::' that stands for one or more groups of zeros. Anything else is marked invalid.
Address categories
IPv4 private ranges are 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 (RFC 1918); loopback is 127.0.0.0/8; link-local is 169.254.0.0/16. For IPv6, fc00::/7 is private (unique local), ::1 is loopback and fe80::/10 is link-local. Everything else counts as public.
CIDR math
For a /N prefix, the subnet mask is N leading 1 bits, the network address is the IP with the remaining host bits zeroed, and the broadcast address (IPv4 only) is the IP with the host bits all set to 1. This is the same math routers use — just computed locally in your browser.

Frequently Asked Questions

Which IP address formats does this tool accept?

Both IPv4 and IPv6. For IPv4, the classic dotted-quad format (e.g. 192.168.1.10) with each octet between 0 and 255. For IPv6, the full 8-group hex form as well as the standard compressed form with a single '::' shortcut (e.g. 2001:db8::1). Leading zeros, extra groups and more than one '::' are rejected.

What does 'private' mean for an IP address?

A private address (RFC 1918 for IPv4: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16; fc00::/7 for IPv6) is meant for internal networks and is not routed on the public internet. This tool also flags loopback (127.0.0.0/8, ::1) and link-local addresses (169.254.0.0/16, fe80::/10). Anything else is treated as a public address.

How is the CIDR information calculated?

Given a prefix length such as /24, the subnet mask is that many leading 1 bits (255.255.255.0 for IPv4). The network address is the IP with the host bits zeroed out, and the broadcast address (IPv4 only) is the IP with the host bits set to 1. All of this is simple bit arithmetic performed in your browser.

Does this tool send my IP address anywhere?

No. The address is parsed entirely with JavaScript in your browser. There is no lookup API, no 'what is my IP' call and no network request of any kind — you can use this tool fully offline once the page has loaded.

What is the decimal representation of an IPv4 address?

An IPv4 address is a 32-bit number, so it can be written as a single decimal integer between 0 and 4,294,967,295. For example 192.168.1.10 is 3232235786 in decimal. This is the form used internally by many network libraries and logs.