Free UUID Generator
Generate cryptographically random version 4 UUIDs — one at a time or fifty — and copy them all with a single click.
Version 4 UUIDs use 122 random bits — collisions are for all practical purposes impossible.
How to use the UUID generator
- Set how many UUIDs you need (up to 50).
- Click Generate — each one is built from your browser’s cryptographic random number generator.
- Copy all grabs the whole list for pasting into code, configs, or database seeds.
What UUIDs are for
A UUID (universally unique identifier) is a 128-bit label like 3f6d4a21-9b7e-4c2d-a1f0-8e6d5c4b3a29 used wherever you need an ID that will never collide: database primary keys, distributed systems, file names, API tokens, and test fixtures. Version 4 means "random" — 122 of the 128 bits come from a secure random source, with 6 bits fixed to mark the version and variant. The chance of two v4 UUIDs colliding is roughly 1 in 5 × 10³⁶, far smaller than the chance of a cosmic ray flipping a bit in your RAM. Because this tool uses crypto.getRandomValues, its output is suitable for anything except high-security secrets — for passwords and tokens, use the dedicated password generator instead.
Frequently asked questions
What does "version 4" mean?
UUID version 4 means randomly generated. The 13th hex digit is always 4 and the 17th is 8, 9, A, or B — those fixed bits identify the version and variant.
Can two UUIDs ever be the same?
In theory yes, in practice no. With 122 random bits you would need to generate about a billion UUIDs per second for 85 years to reach a 50% collision chance.
Are these safe to use as passwords?
They are random enough, but UUIDs are not designed as secrets and their format is recognizable. Use the password generator for credentials.
Is generation private?
Yes — everything happens locally in your browser. Generated UUIDs are never sent anywhere.