UUID Generator
Produce random version 4 UUIDs using your browser's cryptographic random number generator, one at a time or several hundred at once.
How to use it
- Set how many identifiers you need.
- Choose upper case or no dashes if the target system requires it.
- Press Generate and copy the list.
Why it stays private
Identifiers are often created for internal systems before anything is announced, and a sequence of UUIDs can reveal how much data a system holds. Generating them locally keeps that signal private.
Questions
Are these really random?
Yes. They come from the browser's cryptographic random source, the same one used for encryption keys, not from a predictable pseudo-random generator seeded by the clock.
What is a version 4 UUID?
A 128-bit identifier defined by RFC 4122 with the version field set to 4 and the variant field set correctly, meaning all the randomness comes from those random bits. The standard textual form is 36 characters including four hyphens.
Could two UUIDs ever collide?
In practice, no. There are about 3.4 × 10^38 version 4 UUIDs. To reach even a one-in-a-billion chance of a collision you would need to generate around 10^14 of them.