webutilkit

UUID Generator

Generate version 4 UUIDs using your browser’s cryptographically secure random number generator.

Version 4 UUIDs, generated with the browser’s cryptographically secure random number generator.

UUIDs
0 generated
How it works


Each click asks the browser’s crypto.randomUUID() for a fresh version 4
UUID: 122 bits of cryptographically secure randomness formatted as
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where the 4 marks the version and
y is fixed to one of four values by the UUID spec.


Why version 4


Version 4 UUIDs are pure randomness with no embedded timestamp, MAC address,
or counter, which makes them safe to generate offline with no coordination
and no way to trace one back to when or where it was created. That is what
almost everything asking for “a UUID” today means.


Uniqueness in practice


The chance of two random version 4 UUIDs ever colliding is astronomically
small: even generating a billion per second, it would take about 85 years
of continuous generation before the odds of a single collision reached 50%.
Frequently asked questions
Are these generated on a server?
No. Every UUID is generated locally with crypto.randomUUID, a browser API backed by a cryptographically secure random number generator.
How likely is a collision?
A version 4 UUID has 122 random bits. You would need to generate roughly a billion UUIDs per second for about 85 years before the chance of a single collision reached 50%.