A UUID (or GUID) is a 128-bit identifier designed to be unique without a central authority. Version 4 UUIDs are random, making collisions astronomically unlikely. This tool generates cryptographically random v4 UUIDs in your browser — one, or a whole batch.
How to use it
- A fresh UUID appears on load.
- Click Generate for new ones.
- Set quantity for multiple at once.
- Copy one, or Copy All.
About UUID Generator
UUIDs are everywhere: database keys, distributed-system identifiers, correlation IDs, unique file names, API idempotency keys. Their value is that any system can generate one independently and trust it will not collide. Version 4 uses 122 bits of randomness — an astronomically large keyspace. This generator uses the browser crypto source and can produce large batches for seeding test data, all locally.
FAQ
Are these truly unique?
Not guaranteed, but the collision probability is negligible in practice. They are safe to use as identifiers.
UUID vs GUID?
The same thing. GUID is Microsoft’s term; UUID is the RFC 4122 standard term.
Which version?
Version 4, based on random numbers — the most common for general-purpose IDs.