Regex for IPv6 Address

Validates full IPv6 addresses (eight groups of four hexadecimal digits).

Pattern

/^([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$/i

Live Tester

Enter a string to test

Examples

The i flag makes the pattern case-insensitive.

✓ 2001:0db8:85a3:0000:0000:8a2e:0370:7334

✓ fe80:0000:0000:0000:0000:0000:0000:0001

✗ 2001:db8::1

✗ 192.168.1.1

✗ 2001:db8:85a3:0000:0000:8a2e:0370

Pattern Breakdown

([0-9a-fA-F]{1,4}:){7} — seven groups of 1-4 hex digits followed by colon

[0-9a-fA-F]{1,4}$ — final group without trailing colon

Code Snippets

Javascript

const regex = /^([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$/i;
regex.test("2001:0db8:85a3:0000:0000:8a2e:0370:7334"); // true

Python

import re
pattern = r"^([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$"
bool(re.match(pattern, "2001:0db8:85a3:0000:0000:8a2e:0370:7334", re.IGNORECASE))  # True

Php

$pattern = '/^([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$/i';
preg_match($pattern, "2001:0db8:85a3:0000:0000:8a2e:0370:7334"); // 1

Related Patterns

Email Address /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/ URL /^https?:\/\/(www\.)?[a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([a-zA-Z0-9()@:%_+.~#?&/=-]*)$/ Phone Number (International) /^\+?[1-9]\d{1,14}$/ Phone Number (US) /^$?[2-9]\d{2}$?[-.\s]?\d{3}[-.\s]?\d{4}$/ Phone Number (EU) /^\+?[1-9][0-9]{0,3}[\s.-]?$?[0-9]{1,5}$?[\s.-]?[0-9]{1,5}[\s.-]?[0-9]{1,5}$/ IPv4 Address /^((25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(25[0-5]|2[0-4]\d|[01]?\d\d?)$/

Frequently Asked Questions

What is the regex for IPv6 Address?▾

The regex pattern for IPv6 Address is /^([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$/i. Validates full IPv6 addresses (eight groups of four hexadecimal digits).

How do I use the IPv6 Address regex in JavaScript?▾

In JavaScript you create the pattern with a regex literal or the RegExp constructor and call .test() to check a string against it. A ready-to-copy example is shown in the Code Snippets section above, alongside Python and PHP versions.

What does the IPv6 Address pattern match?▾

It matches strings like 2001:0db8:85a3:0000:0000:8a2e:0370:7334; it rejects strings like 2001:db8::1. See the Examples section above for the full list of matching and non-matching cases.