UUID Generator

What is a UUID?

A UUID (Universally Unique Identifier), sometimes called a GUID, is a 128-bit value written as 32 hexadecimal digits in the pattern 8-4-4-4-12, e.g. 3f2504e0-4f89-41d3-9a0c-0305e82c3301. Version 4 UUIDs are generated from random numbers, making collisions astronomically unlikely — perfect for database keys, file names, and request IDs.

Why they're safe to use anywhere

Version 4 UUIDs use 122 random bits — so many possible values that two independent machines can each generate them with no coordination and never realistically collide. That's what makes them ideal for distributed systems, where many servers create records at once without a shared counter.

When to use a UUID

• Database primary keys generated on the client or across services.
• File names and upload IDs to avoid collisions and make guessing hard.
• Idempotency keys so a retried API request isn't processed twice.
• Correlation IDs to trace one request across many logs and services.

For short, human-facing codes (like an order number read over the phone), a UUID is overkill — use a shorter scheme there. Our guide on what a UUID is and when to use one goes deeper, including the different versions.

Generated with real randomness

Each UUID is created in your browser with the Web Crypto API, the same cryptographic randomness used for secure connections. Nothing is uploaded, and you can generate a single ID or a large batch at once.