UUID generator

All UUIDs are generated locally with crypto.getRandomValues. util.work does not see them.

UUID v4UUID v7

CountUppercase

UUIDs

What this UUID tool does

This page generates UUID v4 (random) and UUID v7 (time-ordered) values directly in your browser. The values come from crypto.getRandomValues, so they never travel to a server.

UUID v4 vs v7

UUID v4 is fully random and is the most widely used variant. UUID v7 puts a Unix timestamp in milliseconds at the front of the value, so v7 UUIDs sort in roughly time order. v7 is a good default for new database primary keys because it is more index-friendly than v4.

Common uses

Use UUIDs as database primary keys, idempotency keys, request ids, file names, test fixtures, and any other place where you need a unique identifier without a central allocator.