UUID Generator
Create a batch of universally unique identifiers. Choose the version and how many you need, then copy them all or download as a text file.
How it works
Version 4 is a random UUID: 122 random bits, generated with your browser’s secure random source (crypto.getRandomValues). It’s the default and the right choice for most uses.
Version 1 is time-based: it embeds a timestamp and a node identifier, so UUIDs generated in sequence are roughly sortable. The node portion here is a random 48-bit value.
Frequently asked questions
What’s the difference between v4 and v1?
v4 is purely random — no ordering, maximum entropy. v1 encodes the time of creation, so IDs created later are numerically larger. Use v4 unless you specifically need time-ordered IDs.
Are UUIDs truly unique?
A v4 UUID has 2¹²² possibilities, so collisions are astronomically unlikely in practice. They’re unique for practical purposes, not mathematically guaranteed.