IP validator

Check whether a value is a valid IPv4 or IPv6 address and which family it belongs to. Instant validation in your browser.

Free tool

IP Address Validator

Paste any value and find out instantly whether it is a syntactically valid IPv4 or IPv6 address. Handy for cleaning config files, validating form inputs, or settling the question of whether that log entry is an address at all.

IP validator

Why is 192.168.1.256 invalid?

Each IPv4 octet is one byte, so it runs 0 to 255. Any octet above 255 makes the whole address invalid, no matter how plausible it looks.

Does valid mean the address is reachable?

No — validation checks format only. A valid address can be unassigned, private, or unreachable. Use the ASN lookup or IP map to see what a valid public address belongs to.

This tool also lives in the homepage tool drawer alongside 17 others. Browse everything on the tools page or look up any address with the IP lookup.