UUID Generator
Generate random version 4 UUIDs, one at a time or in bulk. Runs entirely in your browser.
Last updated
How to generate UUIDs
- Choose how many UUIDs you need.
- Choose a format: standard, no hyphens, uppercase or with braces.
- Click Generate, then Copy all.
About v4 UUIDs
A version 4 UUID is a 128-bit identifier built from random or pseudo-random bytes, with a few fixed bits marking its version and variant. The odds of two colliding are vanishingly small, which is why they're used as database keys, request IDs, and other unique identifiers.
Generation uses crypto.randomUUID(), the browser's built-in cryptographically secure random UUID function — no external library, and nothing leaves your device.
Questions about UUIDs
What is a UUID?
A universally unique identifier: 128 bits written as 32 hexadecimal digits in five groups, like 3f2504e0-4f89-41d3-9a0c-0305e82c3301.
Can two version 4 UUIDs be the same?
In theory, but the odds are so small it’s never a practical concern. You’d need to generate billions per second for many years to expect one repeat.
Are these UUIDs secure and random?
Yes. They come from your browser’s crypto.randomUUID(), which uses a cryptographically secure random number generator.
Is a GUID the same as a UUID?
Yes. GUID is Microsoft’s name for the same thing, often written in uppercase with braces, which you can choose as a format.