UUID Generator

A 128-bit identifier written as 32 hexadecimal digits in five groups (like 550e8400-e29b-41d4-a716-446655440000). Version 4 means it's generated from random bits rather than derived from a timestamp or a name - two v4 UUIDs colliding by chance is astronomically unlikely, which is why they're the default choice for database primary keys, session tokens and any identifier that needs to be unique without a central authority handing out numbers.

Real randomness: it uses your browser's built-in crypto.randomUUID() (part of the Web Crypto API), the same cryptographically secure random source used for things like generating encryption keys - not Math.random(), which is fine for games but not designed to be unpredictable.

In practice, no. A v4 UUID has 122 random bits (6 of the 128 bits are fixed to mark the version and variant), so the number of possible values is so large that generating a billion UUIDs a second for a hundred years still wouldn't bring you close to a 50% chance of a collision.

No - generation happens entirely in your browser with no network request involved, and nothing is stored after you leave the page.

Yes - set the count and generate a batch in one click, then copy them all at once, which is faster than generating one, copying, and repeating when you need several for a seed script or test data.