UUID Generator
Generate a random version-4 UUID using your browser's cryptographically secure random number generator — nothing is sent anywhere.
How to generate a UUID
- A fresh UUID is generated the moment the page opens.
- Tap Copy to use it, or Generate for another one.
Frequently asked questions
What is a version-4 UUID?
A 128-bit identifier made almost entirely of random bits, formatted as five hex groups like 123e4567-e89b-42d3-a456-426614174000. The "4" at the start of the third group marks the version.
Can two UUIDs collide?
In theory yes, in practice no — with 122 random bits, you could generate a billion UUIDs per second for decades before a duplicate becomes likely. That's why they're used as database keys without coordination.
How random is it?
It uses the browser's crypto API (crypto.randomUUID or crypto.getRandomValues) — cryptographically secure randomness, not Math.random().