Generate random UUIDs (v4) instantly. Bulk generate, customize format, and copy with one click. Everything runs in your browser — nothing is sent to a server.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is practically guaranteed to be unique across all systems without requiring a central authority. The format is xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where 4 indicates version 4 (random).
When to Use UUIDs
- Database primary keys — UUIDs avoid collisions in distributed systems where auto-increment IDs would conflict.
- API resource identifiers — Expose UUIDs instead of sequential IDs to prevent enumeration attacks.
- Correlation IDs — Track requests across microservices using a unique UUID per request.
- File naming — Generate unique filenames for uploads to avoid overwrites.
UUID v4 vs Other Versions
This generator creates v4 UUIDs (random). Other versions include v1 (timestamp + MAC address), v5 (namespace + name), and v7 (timestamp-ordered, gaining popularity for database use).
Generated UUIDs