UUID Generator (v4 GUID)

Generate up to 100 random version 4 UUIDs at a time. Choose uppercase or no hyphens, then copy the list. They are created in your browser with its secure random number generator and are not stored.

Generate UUIDs

How to generate a UUID

  1. Enter how many UUIDs you need, from 1 to 100.
  2. Tick Uppercase or Remove hyphens if your system needs that format.
  3. Press Generate UUIDs, then Copy all.

What a UUID is

A UUID (universally unique identifier) is a 128-bit value usually written as 32 hex digits in five groups, like 123e4567-e89b-42d3-a456-426614174000. Version 4 UUIDs are random, apart from a few bits that mark the version and variant. The third group always starts with 4.

Can two UUIDs be the same?

A v4 UUID has 122 random bits, so the chance of two matching is so small that it is ignored in practice, even across billions of identifiers. That is why they can be generated independently on many devices without a central counter.

UUID or GUID?

They are the same thing. GUID is the name used in Microsoft products, which often show it in uppercase, sometimes inside braces. Use the uppercase option for those systems.

When not to use a UUID

UUIDs identify things; they are not designed to be secrets. For an access token or password, use the password generator or your framework's token function. Random v4 values are also not ordered by time, which can matter for database index performance. Newer time-ordered formats exist for that case.

Frequently asked questions

How do I generate a UUID?

Press Generate UUIDs. Each line in the box is a new version 4 UUID.

Is a UUID the same as a GUID?

Yes. GUID is Microsoft's name for the same kind of identifier.

Can two UUIDs ever be identical?

In theory yes, in practice no. The odds with 122 random bits are negligible.

What does version 4 mean?

It means the UUID is built from random numbers rather than a timestamp or a name.

How many can I generate at once?

Up to 100 per click. Click again for more.

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