What is a UUID?
A UUID (Universally Unique Identifier), sometimes called a GUID, is a 128-bit value written as 32 hexadecimal characters in five groups, like 550e8400-e29b-41d4-a716-446655440000. It’s used wherever you need an identifier that’s practically guaranteed to be unique without a central authority handing out numbers — database primary keys, file and object names, API request ids, session tokens and more. Version 4 UUIDs, which this tool generates, are made from random data.
How to generate UUIDs
- Choose how many you need (one, or a whole batch).
- Click Generate.
- Copy a single value, or Copy all to grab the whole list at once.
Why UUIDs instead of counting 1, 2, 3?
Sequential ids are simple but reveal how many records exist and are hard to create in advance or across multiple servers without collisions. UUIDs can be generated independently anywhere — on the client, on different servers, offline — and still be unique, which is why they’re popular in distributed systems.
Frequently asked questions
Are they truly unique? Collisions are astronomically unlikely — v4 UUIDs have 122 random bits, so you could generate billions and never repeat one.
What’s the difference between UUID and GUID? They’re essentially the same thing; GUID is Microsoft’s name for it.
Is it private? Yes — UUIDs are generated locally using your browser’s secure random generator.