UUID Generator (v4 & v7)

Generate random v4 or time-ordered v7 UUIDs in bulk, with formatting options.

What is a UUID?

A UUID (universally unique identifier), also called a GUID, is a 128-bit identifier written as 32 hexadecimal characters such as 3f2b8c1e-9d4a-4c6b-8e2f-1a7d5c9e0b34. It is practically guaranteed to be unique without a central registry.

v4 or v7?

Version	How it is made	Best for
v4	122 random bits	General unique IDs, tokens, file names
v7	Unix timestamp in milliseconds + random bits (RFC 9562)	Database primary keys — sorts by creation time, which keeps indexes fast

All UUIDs are generated in your browser with crypto.getRandomValues, a cryptographically secure random generator. Choose formatting options for your language: no hyphens, uppercase (common for Windows GUIDs) or braces.

Frequently asked questions

Can two UUIDs ever be the same?

For v4 the chance is astronomically small — you would need to generate billions per second for many years to expect a collision.

Is a GUID the same as a UUID?

Yes. GUID is Microsoft's name for the same 128-bit identifier.

Why use UUID v7 for databases?

Because v7 values increase over time, new rows are inserted at the end of the index, which is faster than random v4 keys.