simd-prng

A fast, seedable pseudo-random number generator, using WebAssembly and SIMD instructions.

Read the docs

⚠️ This is not a cryptographically secure PRNG. Do NOT rely on it for security ⚠️

Example

Usage in Node:

import { createPrng } from "simd-prng";

// Basic usage
const prng = createPrng();
console.log(prng.randomInt());

// Custom seed
const seed = new Uint32Array([47346587, 98347504]);
const seeded = createPrng(seed);
console.log(prng.randomInt()); // 652389222

// A single integer is also valid as seed
const seeded = createPrng(seed[0]);
console.log(prng.randomInt()); // 2962608483
Copy

Usage in browsers:

// Vite integration
import { init } from "simd-prng/vite";

// library needs to be asynchronously initialized first
const createPrng = await init();

const prng = createPrng();

console.log(prng.randomInt());
Copy

Usage when ESM imports of WebAssembly are available:

import { createPrng } from "simd-prng/wasm";

const prng = createPrng();

console.log(prng.randomInt());
Copy

Details

This library is a straight WebAssembly port of SIMD-oriented Fast Mersenne Twister (SFMT), using Emscripten. The original implementation was designed to leverage SIMD instructions for speed. This port preserves that property using WebAssembly SIMD.

License

The original C source code is licensed under BSD-3-Clause, so we retain it for the rest of the library.