Fastest UUIDv4 with good RNG

Usage no npm install needed!

<script type="module">
  import uuidRandom from 'https://cdn.skypack.dev/uuid-random';



MIT Licence Stable

Generate RFC-4122 compliant random UUIDs (version 4) with better statistical dispersion than Math.random().


npm i uuid-random

Or download the latest release.



Compatible with almost all versions of:

  • Node
  • Babel
  • TypeScript
  • Web browsers


The included benchmark.js as well as independent benchmarks rank this library as the fastest pure JS UUID v4 generator available with cryptographically secure PRNG— almost 20x faster than the most popular library (using latest NodeJS).

npm package performance
portable-uuid 354k ops/sec
uuid 474k ops/sec
id128 6.0M ops/sec
uuid-random (this) 9.7M ops/sec

Results above generated on a 4.20GHz Intel i7-7700K with Node v12.18.0

Why use UUID?

Universally Unique IDentifiers transcend many constraints of traditional incremental integer IDs, especially in distributed systems. In UUID version 4, we essentially generate a random 128-bit value.

We do trade guaranteed uniqueness for extremely probable uniqueness (you would need to do-loop uuid() at max speed for 73,067 years for a 50% chance of one collision). But for that slight cost, we may now generate valid, unique, persistent IDs on any node of a distributed system (e.g. intermittently offline or high-latency clients).

Note, if you plan to use UUIDs for a new project, depending on your requirements, you may consider a more recent standard that addresses some of the shortcomings of UUID, such as flake-id, nanoid, cuid, or ulid.

Example Usage


import uuid from 'uuid-random';
uuid(); // 'f32dc9ae-7ca8-44ca-8f25-f258f7331c55'


var uuid = require('uuid-random');
uuid(); // '0b99b82f-62cf-4275-88b3-de039020f14e'


<script src="uuid-random.min.js"></script>
  uuid(); // 'b96ab5e6-f1e8-4653-ab08-4dd82ea65778'

Validate a UUID v4 String

uuid.test('0b99b82f-62cf-4275-88b3-de039020f14e'); // true

Generate Binary UUIDs

uuid.bin(); // <Buffer 41 db 10 54 b3 61 48 50 87 f1 2f 7b 08 a5 0f 06>


Feel free to open an issue or submit a pull request.