UUID Generator Online - Free UUID v4 & v1 Generator

Features

UUID v1 & v4

Bulk generate (1-100)

Uppercase / lowercase

With / without hyphens

Copy all

How to Use

1. Pick the version (v4 random or v1 timestamp).

2. Set the quantity and formatting options.

3. Click Generate — copy individual UUIDs or copy them all at once.

About this tool

A UUID is a 128-bit identifier written as 32 hexadecimal digits in five groups, like 3f2b8c1e-9d4a-4f6b-8c2e-1a7d5b9e0c34. It lets different systems create IDs independently with a negligible chance of collision, which is why UUIDs are used for database keys, API resources, file names and distributed events. This generator creates version 4 UUIDs from the browser's cryptographically secure random source, or version 1-style UUIDs built from the current timestamp with a random node value instead of your network card's MAC address. Generate one or up to 100 at a time, choose uppercase or lowercase, and remove the hyphens if a system expects a compact 32-character form. Copy a single value or the whole list.

Frequently Asked Questions

What is the difference between UUID v1 and v4?

Version 4 is almost entirely random, so it reveals nothing about when or where it was created. Version 1 includes a timestamp and a node value, making IDs roughly time-ordered. Here the node is random, so it does not expose your MAC address.

Can two UUIDs ever be the same?

In theory yes, in practice no. A v4 UUID has 122 random bits; you would need to generate about a billion UUIDs per second for around 85 years to reach a 50% chance of a single duplicate.

Is a UUID the same as a GUID?

Yes. GUID is Microsoft's name for the same 128-bit identifier format. Some Microsoft tools display GUIDs in uppercase and wrapped in braces, but the value is equivalent.

Are UUIDs good primary keys in a database?

They work well when IDs are created in many places or must not be guessable. Random v4 keys can slow inserts in some databases because they scatter across indexes; time-ordered formats such as UUID v7 or v1 help with that.

Should I use a UUID as a secret token?

Not for security-sensitive tokens such as password reset links. Although v4 UUIDs are hard to guess, dedicated tokens with more entropy from a secure generator are the recommended practice.