Does it match all UUID versions?

Yes. It accepts any hex in the version and variant positions, covering v1 through v8.

How do I match only UUID v4?

Replace the third group with 4[0-9a-fA-F]{3} to require the version-4 marker.

Is it case-insensitive?

Yes. The class includes both a-f and A-F, so upper and lowercase UUIDs both match.

Regex to Match a UUID

Copy the pattern, paste your text below, and see every UUID it finds. Below the tester: the 8-4-4-4-12 layout and how to make it case- or version-strict.

What this pattern matches

This matches a canonical UUID: five hex groups of 8, 4, 4, 4, and 12 characters separated by hyphens. It accepts every version (v1–v8) and both letter cases.

How it works, part by part

[0-9a-fA-F]{8} — the first group of eight hex digits.

-[0-9a-fA-F]{4} — three middle groups of four hex digits each.

-[0-9a-fA-F]{12} — the final group of twelve hex digits.

Version-strict matching

To require a specific version, pin the first digit of the third group — for example -4[0-9a-fA-F]{3}- matches only UUID v4.