About this uuid generator
A UUID is a 128-bit identifier that can be generated anywhere, by anyone, with a near-zero chance of collision — no central registry needed. Developers use them for database keys, file names, session IDs and tracking references.
How to use it
- Choose how many you need.
- Click Generate UUIDs.
- Copy one or the whole batch.
The formula
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx (4 = version, y = 8, 9, a or b)
Worked example
550e8400-e29b-41d4-a716-446655440000 is the classic example UUID from the original RFC.
Frequently asked questions
Can two UUIDs ever collide?
In theory yes, in practice no — you would need to generate billions per second for centuries to reach even odds of one duplicate among random v4 UUIDs.
What does 'version 4' mean?
The random version: 122 of the 128 bits are random, the rest mark the version and variant. Other versions use time or hashes instead.
Are these generated on a server?
No — your browser's crypto source generates them on this page.