UUID Generator

The UUID Generator is a free uuid generator and guid generator that creates version 4 UUIDs — 128-bit identifiers built from 122 bits of cryptographic randomness — one at a time or in batches of up to 1,000. Toggle uppercase output or dash removal to match whatever format your database, API or codebase expects.

A random uuid is the standard way to generate a unique identifier without a central authority handing out sequential numbers — no coordination between servers, no database round-trip to reserve the next ID, no risk of collision between two services generating IDs independently. That makes UUIDs (also called GUIDs) the default choice for database primary keys in distributed systems, request/trace IDs for logging and observability, idempotency keys for API calls, temporary file names, session identifiers and API keys. They're also the identifier of choice whenever two independent systems — a mobile app generating an offline record and a server it will later sync with, for example — need to agree on an ID before either one has talked to the other.

Generation uses your browser's Web Crypto API — specifically crypto.randomUUID() — the same quality of randomness used to generate cryptographic keys, not the predictable Math.random() that many hand-rolled UUID implementations still rely on. Every UUID follows the standard 8-4-4-4-12 hexadecimal layout with the version and variant bits set correctly, so generated IDs are indistinguishable from ones produced by any standard library. There are other UUID versions — version 1 encodes a timestamp and MAC address, version 5 derives an ID deterministically from a namespace and name — but version 4, pure randomness, is the right default for the vast majority of use cases, which is why it's what this tool generates.

Batch generation up to 1,000 at once, plus one-click copy of the whole list, makes it easy to seed a test database or pre-populate fixture data without writing a script.