๐ IP Address Validator
Check on the spot whether an entered string is a validly formatted IPv4 or IPv6 address. For IPv4, it also identifies the address type โ private, loopback, link-local, or public. Everything runs in your browser; nothing is sent anywhere.
How to use
- Enter the IP address string you want to check.
- Whether it's a valid IPv4/IPv6 address, and its address type, are shown automatically.
How the calculation works
An IPv4 address is four numbers from 0 to 255 separated by dots. This tool checks that there are four parts, and that each is one to three digits and no more than 255. It also classifies the address. 10.0.0.0/8, 172.16.0.0/12 (172.16 to 172.31) and 192.168.0.0/16 are private addresses (RFC 1918): free to use on home and office networks but not reachable directly across the internet. 127.0.0.0/8 is loopback (an address referring to the machine itself), and 169.254.0.0/16 is link-local (assigned automatically when DHCP fails). Anything else is shown as public. IPv6 addresses are checked with the browser's own URL parser, so notation such as "::" to compress zeros is handled correctly.
Worked example
192.168.1.1 โ IPv4, private (common on home routers) 127.0.0.1 โ IPv4, loopback 8.8.8.8 โ IPv4, public 256.1.1.1 โ invalid, since 256 exceeds 255 2001:db8::1 โ valid IPv6 (2001:db8::/32 is reserved for documentation)
Things to be aware of
- This checks format only; it cannot tell you whether the address is in use or reachable.
- Only private, loopback and link-local ranges are identified. Carrier-grade NAT (100.64.0.0/10), multicast (224.0.0.0/4) and broadcast (255.255.255.255) are also shown as public.
- Leading zeros such as "010.1.1.1" are accepted, but some software interprets them as octal.
- IPv6 address types (such as link-local) are not identified.
FAQ
Can this tell me whether the IP address is actually in use?
No โ this tool only checks whether the string is correctly formatted. It cannot tell you whether that address is actually active on a network.
What is a private IP address?
The ranges 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 are reserved for private networks and aren't routed directly on the public internet โ commonly seen behind home routers.
Is the IP address I enter sent to a server?
No. All validation happens entirely in your browser's JavaScript; nothing is ever sent anywhere.