UUID Generator

Generate universally unique identifiers (UUID v4) with cryptographically secure randomness. Create one at a time or generate up to 100 in bulk, then copy or download them. Everything runs locally in your browser.

UUID v4

077a0026-bc9a-4e8c-abf0-59dfcb6fcf99

Bulk Generate

UUIDs are generated entirely in your browser using crypto.randomUUID() and are never transmitted anywhere.

How it works

This tool generates version 4 UUIDs using crypto.randomUUID(), the browser's built-in cryptographically secure UUID generator. Each UUID contains 122 random bits, producing identifiers with an astronomically low probability of collision — you could generate one billion UUIDs per second for about 85 years before having a 50% chance of a single duplicate.

What is a UUID?

A Universally Unique Identifier (UUID) is a 128-bit label used to uniquely identify resources in distributed systems without a central authority. The v4 variant uses random numbers as its source, making it ideal for database primary keys, session tokens, file names, and any scenario where you need a guaranteed-unique string without coordination between systems.

UUID v4 format

A UUID v4 follows the pattern xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where x is any hexadecimal digit and y is one of 8, 9, a, or b. The 4 indicates the version, and the constrained y digit indicates the variant. The remaining 122 bits are random.