UUID Generator

About UUIDs

A UUID (Universally Unique Identifier) is a 128-bit value written as 36 characters, like f47ac10b-58cc-4372-a567-0e02b2c3d479. Version 4 UUIDs are generated from random data — with 122 random bits, the chance of two ever colliding is negligible, which is why they're the default choice for database keys, request IDs, and distributed systems.

Frequently asked questions

Are these UUIDs cryptographically secure?

Yes. They come from crypto.randomUUID() / crypto.getRandomValues(), the browser's CSPRNG — the same quality of randomness used for encryption keys.

What's the difference between UUID v4 and v7?

v4 is fully random. v7 (newer) embeds a millisecond timestamp in the first bits so IDs sort by creation time — better for database index locality. For general uniqueness, v4 remains the standard.

Can two generated UUIDs collide?

Theoretically yes, practically no: you'd need to generate about 2.7×10¹⁸ UUIDs to reach even a 50% chance of a single collision.