A UUID — universally unique identifier — is a 128-bit value used as a database key, a request ID, a filename or any label that must never collide with another. The UUID Generator creates cryptographically random version-4 UUIDs, one at a time or many at once, so developers and testers always have a fresh batch of unique identifiers on hand.
How to use the UUID Generator
- Choose how many UUIDs you need.
- Click Generate.
- Copy the whole list.
Why UUIDs instead of counting
Sequential IDs (1, 2, 3…) require a central authority to hand them out and reveal information like how many records exist. UUIDs solve both problems: any system can generate one independently, with virtually no chance of two machines ever producing the same value. That makes them ideal for distributed systems, offline-first apps, merge-friendly databases and any situation where IDs must be created in many places without coordination.
Tips for using UUIDs
- Version 4 is random, the most common general-purpose choice.
- Collisions are astronomically unlikely, so you can treat them as guaranteed unique in practice.
- Generate in bulk when seeding test data or fixtures.
- Store them as text in the standard 8-4-4-4-12 hyphenated format.
Each UUID is built from secure random bytes in your browser, so nothing is requested from or sent to a server.
Quick reference
| Property | Detail |
|---|---|
| Version | 4 (random) |
| Source | crypto.getRandomValues |
| Bulk | Generate many at once |
| Format | 8-4-4-4-12 hex |
| Processing | Local |