UUID Generator
Generate UUID v4 (random) or UUID v7 (time-sorted) identifiers. Bulk generate, format, and copy.
0 UUIDs generated
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is unique across space and time. UUIDs are used as primary keys in databases, API identifiers, session tokens, and anywhere you need a globally unique ID without coordinating with a central authority.
UUID v4 vs UUID v7
| Feature | UUID v4 | UUID v7 |
|---|---|---|
| Generation | Random | Time-sorted + random |
| Sortable | No | Yes (by creation time) |
| Database Index | Poor (random inserts) | Excellent (sequential) |
| Privacy | No timestamp leaked | Contains creation timestamp |
| Standard | RFC 4122 | RFC 9562 (2024) |
| Use Case | General purpose | Database primary keys |
When to Use UUIDs
- Database primary keys: Use UUID v7 for better index performance
- API resource IDs: Use UUID v4 for unpredictability
- Distributed systems: Generate IDs without central coordination
- File names: Avoid collisions in file uploads and storage
- Correlation IDs: Track requests across microservices
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