UUID Generator Online: Generate v4, v7, and Bulk UUIDs

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hex characters in 5 groups:

550e8400-e29b-41d4-a716-446655440000

UUIDs are used as primary keys in databases, session tokens, request IDs, and anywhere you need a globally unique identifier without a central coordinator.

UUID v4 vs UUID v7

When to Use UUID v7

UUID v7 is the modern choice for database primary keys. Because it's time-ordered, new rows are always inserted at the end of the index — dramatically better performance than v4's random inserts which cause page splits.

Use v7 for:

• Database primary keys (PostgreSQL, MySQL, SQLite)
• Event IDs and log entries
• Any ID that benefits from chronological ordering

Use v4 for:

• Session tokens (unguessable, non-sequential)
• One-time codes
• Cases where ordering leaks timing information

Generate UUIDs in Different Languages

# JavaScript (browser)
crypto.randomUUID() // v4

# Node.js
const { v4: uuidv4 } = require('uuid');
uuidv4();

# Python
import uuid
str(uuid.uuid4())

# Go
import "github.com/google/uuid"
uuid.New().String()

# PostgreSQL
SELECT gen_random_uuid(); -- v4
SELECT uuid_generate_v4(); -- v4 (requires uuid-ossp)

Bulk UUID Generation

Our UUID Generator supports bulk generation — generate 1 to 100 UUIDs at once and copy them all. Useful for seeding databases, generating test data, or creating batch identifiers.

UUID v7 Generator

We also have a dedicated UUID v7 Generator that uses the uuidv7 library to generate properly formatted time-ordered UUIDs. Copy one or generate a batch.