UUID Generator

How to use the UUID Generator

1. Choose how many UUIDs to generate.
2. Tick Uppercase if you need capital letters, as some Microsoft tools prefer.
3. Tick Remove hyphens for a compact 32-character format.
4. Click Run to generate your UUIDs.

How the UUID Generator works

A version 4 UUID is 128 bits, of which 122 are random. The generator uses your browser's cryptographically secure random number generator, then sets the fixed version bits (the 4 at the start of the third group) and variant bits (8, 9, a or b at the start of the fourth group) as required by RFC 9562.

With 2¹²² possible values, you'd need to generate around a billion UUIDs per second for about 85 years before the chance of a single duplicate reached 50%, so they're safe to use as database keys and identifiers without coordination.