3 ways to generate random UUID v4 in Node.js

How to generate random UUID v4 in Nodejs.

There are 3 ways to do that.

This article shows the 3 ways with code examples.

Table of Contents

1. Use built-in crypto module
2. Install UUID module
3. Create UUID utility method
Related articles

1. Use built-in crypto module

The first way is to use the built-in module crypto.

NOTE : Node.js 14.17.0 or later only

Sample code to generate UUID v4 in node.js :

const crypto = require("crypto");
const uuid = crypto.randomUUID()
console.log(uuid);
  // => 5db856b3-197b-4101-8b8d-9f43a60cef4c

Quote : crypto.randomUUID() :

Generates a random RFC 4122 version 4 UUID. The UUID is generated using a cryptographic pseudorandom number generator.

https://nodejs.org/docs/latest-v14.x/api/crypto.html#crypto_crypto_randomuuid_options

Note : Only works with Node.js 14.17.0 or later.

If you are using older Node.js than that, try the following alternatives.

2. Install UUID module

The second way is to use UUID module.

Most recommended module is uuidjs/uuid library.

Github : https://github.com/uuidjs/uuid

Install uuid module via npm :

$ npm install uuid

Sample code to generate random UUID v4 :

import { v4 as uuidv4 } from 'uuid';
const uuid = uuidv4(); 
console.log(uuid);
  /// => 84b0ad70-e320-4c45-935e-4333ba062489

So easy to use.

In addition, this module supports UUID v1 through v3.

3. Create UUID utility method

The last way is to create UUID method by your own.

Sample code to create UUID method in Node.js :

const uuidv4 = () => {
  return ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g,c =>
    (c^(crypto.randomBytes(1)[0]&(15>>(c/4)))).toString(16)
  );
};

const uuid = uuidv4();
console.log(uuid);
  /// => 74f7c0bf-abbe-4ce1-b1cc-98ac43a9d9c1

Whether it is practical or not has not been tested.

The articles below may be helpful.

Make fixed length random number / string in JavaScript with sample codes

Bye 🙂

Code Ronna