UUID Generator
Generate random version-4 UUIDs instantly. Cryptographically random, free, and private, generated in your browser.
Calculator by Toolsloft ↗…Generate random version-4 UUIDs in your browser for use as database keys, request IDs, or any identifier that needs to be unique. Each click produces a fresh UUID locally, with nothing sent to a server.
How this is calculated
It draws 16 random bytes from the browser crypto.getRandomValues source, sets the version nibble to 4 and the variant bits to 10xx per RFC 4122, then formats the bytes as the standard 8-4-4-4-12 hexadecimal string.
How to use
- Click Generate to create a new UUID.
- Copy it with one click.
- Generate as many as you need.
Examples
- Format:
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx - Example:
01234567-89ab-4def-8123-456789abcdef
FAQ
- What is a version-4 UUID?
- A UUID generated from random numbers, with the version (4) and variant bits fixed per RFC 4122. Collisions are astronomically unlikely.
- Are these UUIDs cryptographically random?
- Yes. They use the browser crypto.getRandomValues source, not Math.random.
- Can I use these in production?
- Yes. They are standard RFC 4122 v4 UUIDs suitable for database keys, request IDs, and more.