UUID Generator
Generate 1 to 10,000 version-4 UUIDs in one click, straight from your browser's operating-system entropy pool. Copy the whole batch with one button.
How UUID v4 randomness works here
A version-4 UUID is 122 bits of randomness plus 6 fixed version/variant bits, formatted as 32 hex digits in the familiar 8-4-4-4-12 pattern. This page fills those bits with crypto.getRandomValues(), the same cryptographically secure random source your operating system provides to browsers — not Math.random(), which is predictable and should never be used for identifiers that need to be unguessable.
Collision math in plain terms: even if every person on Earth generated one billion UUIDs every second since the Big Bang, the chance of any two colliding would still be vanishingly small. That is what makes UUIDs practical as database primary keys, idempotency keys, and session identifiers without a central authority handing them out. Generated values never leave your machine and this page cannot log them — there is no server to log them on.
FAQ
- Are these really random?
- Yes — sourced from
crypto.getRandomValues(), the OS entropy pool exposed to the browser. - Why would I choose no-dash format?
- Some databases and URL builders expect 32 hex chars without separators; the value carries the same entropy either way.
- Is there a limit?
- This page caps the batch at 10,000 to keep the tab responsive. Need more? Generate twice.