UUID Generator Guide: Create v4 UUIDs Online

2026-05-24

Quick Answer

Quick Answer: Use our free UUID Generator to create RFC 4122 version-4 UUIDs instantly. Generate 1–100 at once and copy with one click—all in your browser.

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit value, usually shown as xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. Version 4 UUIDs are random and widely used for database primary keys, session IDs, and file names.

When to use UUID v4

Database IDs — avoid sequential ID leaks
API request tracing — correlate logs across services
Test fixtures — placeholder user or order IDs
File uploads — unique object keys in storage

Generate UUIDs in code

JavaScript (modern browsers & Node 19+)

crypto.randomUUID();
// "f47ac10b-58cc-4372-a567-0e02b2c3d479"

Command line (macOS/Linux)

uuidgen

Try It Yourself

Need UUIDs right now? Open the UUID Generator →

Frequently Asked Questions

Is UUID v4 guaranteed unique?

Collisions are astronomically unlikely for practical use. For strict guarantees in distributed systems, consider UUID v7 or ULID for sortable IDs.

UUID vs GUID?

GUID is Microsoft's name for the same idea. UUID v4 from our tool follows the standard RFC 4122 format.