UUID generator

Generate unique UUIDs (GUIDs) - random v4 or time-ordered v7 - and see what's inside an existing one.

Everything happens in your browser - nothing you type here is sent to any server.

How it works

v4 or v7

UUID v4 is completely random - 122 random bits make a repeat practically impossible. UUID v7 starts with its creation time in milliseconds, so new IDs sort chronologically. That matters in databases: the index grows in order instead of inserting entries at random places, which makes writes faster.

Secure randomness

The IDs come from the browser's cryptographic random number generator (crypto.getRandomValues), the same one used for encryption keys - not from Math.random().

Frequently asked questions

Are UUID and GUID the same thing?

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

Can two UUID v4s collide?

In theory yes, in practice no: you'd need to generate billions of IDs every second for decades for the chance to be noticeable.

Can you read the date from a UUID v7?

Yes - paste it into “Inspect a UUID”. So don't use v7 where the moment a record was created should stay hidden.