UUID Generator

Generate RFC 4122 compliant UUIDs (Universally Unique Identifiers). Version 4 UUIDs are randomly generated and have 122 bits of entropy.

Format

Version:v4Entropy:122 bits

Generated Values

Usage Examples

SQL (Primary Key)

CREATE TABLE users (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  email VARCHAR(255) NOT NULL
);

INSERT INTO users (id, email) VALUES 
  ('uuid-here', '[email protected]');

JavaScript

// Native (Node.js 14.17+ / modern browsers)
const uuid = crypto.randomUUID();

// With uuid package
import { v4 as uuidv4 } from 'uuid';
const id = uuidv4();

UUID v4 structure

xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx

The 4 indicates version 4 (random)
The y is one of 8, 9, a, or b (variant 1)
All other characters are random hex digits
Total: 32 hex characters = 128 bits (122 random + 6 version/variant)

Bulk Generation

GenerateUUIDs

Generate in Terminal

macOS / Linux

$uuidgen

Linux (kernel)

$cat /proc/sys/kernel/random/uuid

Python

$python3 -c "import uuid; print(uuid.uuid4())"

Node.js

$node -e "console.log(require('crypto').randomUUID())"