UUID Generator
Generate random v4 UUIDs, one or a thousand at a time.
About this uuid generator
A UUID is a 128-bit identifier designed so that anyone can generate one at any time without coordinating with anyone else, and still be confident it has never been produced before.
Version 4 UUIDs are simply 122 random bits with six fixed. The odds of a collision are so small that you would need to generate a billion a second for about 85 years to have a 50% chance of one.
How to use it
- Choose how many you need.
- Pick a format — lowercase with hyphens is the standard.
- Generate, then copy the list.
UUID Generator — FAQ
Are these safe to use as database keys?
Yes. They come from crypto.getRandomValues, the browser's cryptographic random source. Note that random UUIDs as a clustered primary key can hurt insert performance in some databases; UUIDv7 or a sequential key is often the better choice there.
What is the difference between UUID versions?
v1 embeds a timestamp and MAC address, v4 is random, and v7 is time-ordered random. v4 is the right default when you just need an identifier with no meaning attached.
Can two UUIDs ever be the same?
In principle yes, in practice no. With 122 random bits, collisions are far less likely than a hardware failure corrupting your data instead.