UUID generator

About this tool

A UUID is a 128-bit identifier written as 32 hex digits split by dashes, such as f47ac10b-58cc-4372-a567-0e02b2c3d479. This tool generates version 4 (fully random) and version 7 (a timestamp followed by random bits, so IDs sort in creation order) UUIDs, one at a time or hundreds at once.

Generation happens entirely in your browser using the Web Crypto API. Nothing is sent anywhere, so you can generate as many IDs as you need for a database migration or a test fixture without leaving a trace on a server.

Common uses: primary keys for a new database table, request IDs for logging and tracing, or filler data for tests and mocks. Pick v7 when you want IDs that also work as a rough timestamp and sort well in a database index; pick v4 when you just need a unique, unguessable value. See RFC 9562 for the format, and MDN’s crypto.randomUUID() reference for how the browser generates the randomness.