UUID Generator (v4)
Cryptographically random version 4 UUIDs, generated locally in your browser. Nothing leaves this page.
Click Generate to create 5 UUIDs.
NIL UUID
00000000-0000-0000-0000-000000000000
The special all-zeros UUID defined by RFC 4122 — often used as a placeholder or sentinel value.
About v4 UUIDs
A version 4 UUID contains 122 bits of cryptographic randomness (6 of the 128 bits are fixed to mark the version and variant). With that much entropy, collisions are effectively impossible in practice: you would need to generate about 2.7 quintillion UUIDs to reach even a 50% chance of a single duplicate. This page uses your browser's crypto.randomUUID (falling back to crypto.getRandomValues), never Math.random.