UUID Generator
Generate one or many RFC 4122 version-4 UUIDs with a cryptographic random source.
What is a UUID?
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value written as 32
hexadecimal digits in the pattern 8-4-4-4-12. Version 4 UUIDs are almost entirely random,
which lets independent systems mint identifiers that will not collide without ever coordinating.
Where the randomness comes from
This generator calls crypto.randomUUID(), backed by the browser's cryptographically
secure random source, and falls back to crypto.getRandomValues() on older browsers. That
makes the output suitable for keys, correlation IDs and idempotency tokens.
How to use the UUID Generator
- Set the count. Choose how many UUIDs you need, from 1 up to 1000.
- Click Generate. A fresh batch appears, one UUID per line.
- Copy them all. Use Copy all to grab the whole list at once.
- Regenerate freely. Click again any time for a brand-new set.
Frequently asked questions
Which UUID version is this?
Version 4 — the random variant. The 13th hex digit is always 4 and the 17th is one of 8, 9, a or b, as the spec requires.
Are these UUIDs really unique?
Collisions are astronomically unlikely: a v4 UUID has 122 random bits, so you would need to generate billions before any realistic chance of a repeat.
Are they cryptographically random?
Yes. They come from the browser crypto API, not Math.random, so they are unpredictable.
Is anything logged or stored?
No. Generation happens in your browser and nothing is transmitted or saved.