What counts as a valid IPv4 address?

Four decimal numbers from 0–255 separated by dots, with no leading zeros (like 192.168.01.1, which some systems misinterpret as octal). This tool rejects out-of-range octets, extra or missing segments, and leading-zero segments, which is stricter — and safer — than a naive regex check.

What counts as a valid IPv6 address?

Eight groups of 1–4 hexadecimal digits separated by colons, where one run of consecutive all-zero groups may be collapsed to a double colon (::) — but only once. This tool expands any compressed address to its full 8-group form and also produces the shortest valid compressed form, so you can compare both representations.

What do "private", "loopback", and "multicast" mean?

Private ranges (like 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, or IPv6 fc00::/7) are reserved for internal networks and never routed on the public internet. Loopback (127.0.0.1 or ::1) refers to the device itself. Multicast addresses deliver one packet to many listeners at once. Knowing the type helps you spot misconfigured firewall rules or DNS records pointing at the wrong kind of address.

Is my IP address sent anywhere when I use this tool?

No — the entire check runs in JavaScript in your browser tab. Nothing is sent to a server, logged, or stored, which matters if you're validating an internal or sensitive address.

IP ADDRESS VALIDATOR

Validate IPv4 and IPv6 addresses, see them expanded and compressed, and find out whether they're public, private, loopback, or multicast.

IP address

Valid IPv4 address

Octets	192 . 168 . 1 . 1
Binary	11000000.10101000.00000001.00000001
Type	Private (RFC 1918)

How to validate an IP address

1
Type or paste an IPv4 address (like 192.168.1.1) or an IPv6 address (like 2001:db8::1).
2
The validator detects the version automatically and checks every octet or group.
3
Read the breakdown: binary form for IPv4, expanded/compressed form for IPv6, and the address type.

Questions

What counts as a valid IPv4 address?: Four decimal numbers from 0–255 separated by dots, with no leading zeros (like 192.168.01.1, which some systems misinterpret as octal). This tool rejects out-of-range octets, extra or missing segments, and leading-zero segments, which is stricter — and safer — than a naive regex check.
What counts as a valid IPv6 address?: Eight groups of 1–4 hexadecimal digits separated by colons, where one run of consecutive all-zero groups may be collapsed to a double colon (::) — but only once. This tool expands any compressed address to its full 8-group form and also produces the shortest valid compressed form, so you can compare both representations.
What do "private", "loopback", and "multicast" mean?: Private ranges (like 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, or IPv6 fc00::/7) are reserved for internal networks and never routed on the public internet. Loopback (127.0.0.1 or ::1) refers to the device itself. Multicast addresses deliver one packet to many listeners at once. Knowing the type helps you spot misconfigured firewall rules or DNS records pointing at the wrong kind of address.
Is my IP address sent anywhere when I use this tool?: No — the entire check runs in JavaScript in your browser tab. Nothing is sent to a server, logged, or stored, which matters if you're validating an internal or sensitive address.