UUID Generator
v4 & v7 unique identifiers
Examples
Random v4 UUID
Version: v4 · Quantity: 1
f47ac10b-58cc-4372-a567-0e02b2c3d479
Uppercase, braced
Case: ABC · Braces: on
{F47AC10B-58CC-4372-A567-0E02B2C3D479}Frequently asked questions
Are these UUIDs generated on a server?
No. Every UUID is produced locally in your browser using the Web Crypto API (crypto.randomUUID / crypto.getRandomValues). Nothing is uploaded — the identifiers never leave your machine.
What's the difference between v4 and v7?
v4 is fully random — the go-to for general-purpose unique IDs. v7 embeds a millisecond Unix timestamp in its leading bits, so v7 UUIDs sort chronologically, which makes them friendlier as database primary keys.
Are these UUIDs cryptographically random?
The random bits come from the Web Crypto API's cryptographically secure generator, the same source browsers use for crypto.randomUUID. They're suitable as unique identifiers, though a UUID is an ID, not a secret.
What is the nil UUID?
The nil UUID is the all-zero value 00000000-0000-0000-0000-000000000000. It's a defined special case used as a placeholder or "no value" sentinel.