UUID Generator

Create random version 4 UUIDs for databases, APIs and test data. Generate one or a thousand at a time.

How many

Hyphens Uppercase Braces {} Quotes and commas (for code)

Your UUIDs

How to generate UUIDs

Enter how many UUIDs you need, up to 1,000.
Choose the format. The standard format has hyphens and lowercase letters.
Click Copy all or download them as a text file. Press Generate new for a fresh batch.

Format options

Option	Example
Standard	`9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d`
No hyphens	`9b1deb4d3b7d4bad9bdd2b0d7b3dcb6d`
Uppercase with braces	`{9B1DEB4D-3B7D-4BAD-9BDD-2B0D7B3DCB6D}`
Quotes and commas	`"9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d",`

The quotes and commas option is handy when you want to paste a list of IDs straight into a JavaScript array, a JSON file or a SQL IN (...) clause.

When to use UUIDs

Database primary keys when records are created in several places, like mobile apps that work offline.
Public IDs in URLs, where you do not want people guessing the next record by adding 1 to a number.
File names for uploads, so two users uploading "photo.jpg" never clash.
Test data and fixtures for development.

How to spot a version 4 UUID

Look at the first character of the third group. In a v4 UUID it is always a 4. The first character of the fourth group is always 8, 9, a or b. Those fixed bits tell software which version and variant it is dealing with.

Frequently asked questions

What is a UUID?

A UUID (universally unique identifier) is a 128 bit ID written as 32 hex characters in five groups, like 3f2b8c1e-9d4a-4f7b-a2c6-0e5d1b7f9a34. It lets different systems create IDs on their own without checking with each other first.

Is a GUID the same as a UUID?

Yes. GUID is the name Microsoft uses. They follow the same standard and you can use them the same way.

Can two UUIDs ever be the same?

In theory yes, in practice no. A version 4 UUID has 122 random bits. You would need to create about a billion UUIDs every second for 85 years to have a 50 percent chance of a single duplicate.

Should I use UUID v4 or v7?

Version 4 is fully random and the most widely supported. Version 7 starts with a timestamp, so new IDs sort in order, which can make database indexes faster. If your database or framework supports v7 natively, it is worth considering for primary keys.