How to Generate a UUID in JavaScript

Modern JavaScript can generate cryptographically strong UUIDs with one line — no library needed.

The modern way: crypto.randomUUID

const id = crypto.randomUUID();
// "550e8400-e29b-41d4-a716-446655440000"

This is built into all modern browsers and Node.js 16+. It returns a version 4 UUID using a cryptographically secure random source. This is what you should use.

In Node.js

crypto.randomUUID works in Node too:

import { randomUUID } from 'node:crypto';
const id = randomUUID();

Don't use Math.random

You'll see snippets that build UUIDs from Math.random(). Avoid them:

• Math.random() is not cryptographically secure and can produce predictable or colliding values.
• It's unnecessary now that crypto.randomUUID exists.

Need v7 (sortable)?

crypto.randomUUID produces v4. For time-ordered v7 UUIDs (great for database keys), use a small library like uuidv7, since they aren't built in yet.

Generate without code

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