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Network & IP Calculation Tools

IPv6 Validator

Validate IPv6 by parsing each group, with proper handling of ::, hexadecimal group counts, and embedded IPv4 tails.

Leading and trailing spaces are ignored; the address itself is not corrected automatically.

Parse and validate full, compressed, and IPv4-mapped IPv6 addresses, then generate expanded and canonical compressed forms.

Your input is processed only in your browser and is never uploaded to a server.

What this tool does

Rather than merely checking for colons or relying on one enormous regular expression, the IPv6 Validator parses an address into eight 16-bit groups. It supports full notation, one :: compression marker, loopback, unspecified, and link-local addresses, plus canonical embedded IPv4 notation at the end.

  • Each regular hexadecimal group must contain one to four characters from 0-9, a-f, or A-F.
  • :: may appear at most once and must represent at least one all-zero group.
  • Expanded output always uses eight four-digit lowercase hexadecimal groups. Compressed output uses the longest run of zero groups, choosing the leftmost run in a tie.

How to use it

  1. Enter a full or compressed IPv6 address.
  2. Click Validate IPv6.
  3. View the validation status, expanded address, and compressed address.
  4. Copy the normalized representation you need.

How it works

The parser first converts a valid embedded IPv4 tail into two 16-bit groups, then checks the number of :: markers, the explicit group count, and each group’s range. It inserts the missing zero groups to make eight in total; compression uses the longest zero run and the leftmost run when lengths tie.

Examples

  • 2001:db8::1 → Expands to 2001:0db8:0000:0000:0000:0000:0000:0001.
  • ::ffff:192.168.1.1 → Valid and can be normalized as ::ffff:c0a8:101.
  • 2001::db8::1 → Invalid because :: appears twice.

Common uses

  • Validate IPv6 strings in network configurations or documentation.
  • Normalize an address between expanded and shortened forms.
  • Check whether an IPv4-mapped IPv6 tail is valid.

Privacy

Inputs and results are processed only in local browser memory. Nothing is uploaded, sent to an online API, or stored automatically.

IPv6 Validator Features

Parse and validate full, compressed, and IPv4-mapped IPv6 addresses, then generate expanded and canonical compressed forms. Useful for network planning, configuration checks, and troubleshooting; results can be reviewed and copied immediately.

FAQ

How many bits are in an IPv6 address?

An IPv6 address contains 128 bits and is typically written as eight 16-bit hexadecimal groups.

What does :: mean in an IPv6 address?

It represents one or more consecutive all-zero groups and can be used only once in an address.

What address is ::1?

::1 is the IPv6 loopback address, equivalent to 127.0.0.1 in IPv4.

Does IPv6 validation connect to the network?

No. The page only parses the input string; it does not query routing, DNS, WHOIS, address ownership, or connectivity.

IPv4 Validator

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