How to Generate a UUID (Version 4) for Free
UUIDs show up as IDs in databases, APIs and config files. This guide explains what a version 4 UUID is and when to use one.
What is the UUID Generator?
A UUID (universally unique identifier) is a 128-bit label written as 32 hexadecimal characters in five groups. This tool creates a version 4 UUID, where most bits are random, so each result is practically unique. It uses the browser's built-in random UUID function when available and falls back to a Math.random-based generator otherwise, and nothing is sent anywhere.
How to use it
- Click Generate UUID.
- Copy the UUID shown.
- Paste it wherever you need a unique identifier.
Worked example
Clicking Generate UUID produces a value in the standard 8-4-4-4-12 format, for example a string like 123e4567-e89b-42d3-a456-426614174000 (the actual value is random each time).
What does a version 4 UUID look like?
It is 36 characters long: 32 hexadecimal digits in groups of 8, 4, 4, 4 and 12, separated by hyphens, with a 4 in the version position.
Frequently asked questions
Is a version 4 UUID guaranteed to be unique?
No generator can promise absolute uniqueness, but with 122 random bits a collision is so unlikely that version 4 UUIDs are used as unique IDs in practice.
Does this tool send anything to a server?
No. The UUID is generated locally in your browser and is never uploaded or stored.