A tiny (~260B) and super fast RFC4122 compliant v4 UUID generator.

Supports both Nodejs and Browser environments while using native cryptography features.

Includes ESM and Commonjs/Nodejs bundles. Allows bundlers like Webpack and Rollup to pick the correct bundle for different environments.

Check out the playground

$ npm install @alizeait/uuid

import { v4 } from "@alizeait/uuid";

v4(); //  'dc8c63d6-55e0-49be-9d68-19b0e51be2a6'
v4(); //  'e3f68a1e-d22b-4c94-bc6b-78b44c1608f3'

uuid/v4               x 1,006,107 ops/sec ±1.04% (82 runs sampled)
@alizeait/uuid        x 4,262,898 ops/sec ±0.98% (87 runs sampled)
nanoid                x 1,779,066 ops/sec ±1.58% (91 runs sampled)


RFC UUID v4 validation:

uuid/v4               ✔
@alizeait/uuid        ✔
nanoid                ✘

Running on Node.js v12.13.0, 64-bit OS, Intel(R) Core(TM) i5-6600K CPU @ 3.50GHz, 16.0 GB RAM

It first fills a large(6144 bytes) Uint8Array typed array buffer with cryptographically strong random values using the browser/nodejs crypto API(Meaning that it fills an array buffer randomly with numbers between 0 and 255). It then generates an array of 2 digit hexadecimal numbers(length=256) and starts slicing off chunks from the buffer as needed, meaning that each buffer is able to supply 384 v4 UUID random invocations. When the buffer is all used up, it generates a new one with the crypto APIs and iterates.

This caching mechanism allows for faster composition and generation of the uuids.