Identifiers tools

Generate a value that has to be unique, and understand what it encodes.

A UUID carries its version in one nibble and, in v1 and v7, a timestamp you can read back out. Which version you pick decides whether your values sort by creation time and how badly they fragment a database index. Generation here uses crypto.getRandomValues with rejection sampling rather than Math.random and a modulo, because a modulo over a random byte quietly makes the low values more likely.

Free, with no sign-up. Every one runs entirely in your browser: nothing you paste is uploaded, and there is no server to send it to.