Free · Private · Client-side

UUID Generator

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

Generated values never leave this device.

Format

Version:v4

Collision odds: you could generate 1 billion UUIDs every second for about 85 years before reaching a 50% chance of a single collision.

Estimated entropy: 122 bits · UUID v4 · 122 random bits of 128~6.1 million times the age of the universe to crack

Weak · <50 bitsFairGood · 70+Strong · 100+

In plain terms: a gaming PC guessing a million passwords per second would need 6.1 trillion times the age of the universe. Even someone renting every cloud server on Earth — a trillion guesses per second — would need 6.1 million times the age of the universe. Nobody is guessing this password; the only realistic risks are it being reused or phished.

Generated UUIDs

Strong122 bits

Bulk:Exported files contain sensitive values — delete after use.

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', 'user@example.com');

JavaScript

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

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

Random UUID v4 (uuidv4) Generator

A uuidv4 is a random 128-bit identifier defined by RFC 4122. Unlike v1 UUIDs, which embed a timestamp and MAC address, a version 4 UUID is built almost entirely from random bits: 122 of its 128 bits are random, and the remaining 6 mark the version and variant.

This random UUID generator draws 16 bytes from the Web Crypto API in your browser, sets the version-4 and variant bits, and formats the result as 32 hex characters. Nothing is sent to a server, and no UUID is logged or stored.

Use the Format option above to output lowercase, uppercase, or no-dash GUIDs, regenerate a single row, or download a bulk CSV of random UUIDs.

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)

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())"