UUIDs give you globally unique identifiers without needing a central authority to hand them out. This generator creates version-4 (random) UUIDs locally, in any quantity.
Why version 4?
Version-4 UUIDs are generated from random numbers, so they need no coordination — any machine can mint one that won't clash with another's. That makes them ideal for database keys, request IDs and distributed systems.
How unique is 'unique'?
With 122 bits of randomness, the number of v4 UUIDs is about 5 × 10³⁶. The probability of a collision is so small that it's safely ignored in virtually every real-world application.
Frequently asked questions
A Universally Unique Identifier is a 128-bit value written as 36 characters (e.g. 550e8400-e29b-41d4-a716-446655440000). Version 4 UUIDs are almost entirely random, making collisions astronomically unlikely.
For practical purposes, yes. A v4 UUID has 122 random bits, so you'd need to generate billions per second for many years before a collision became likely.
Yes — they use the browser's crypto.randomUUID(), backed by a cryptographically secure random number generator, entirely on your device.