UUID Generator
Generate cryptographically secure UUID v4 (random) identifiers for unique identification across systems.
UUID Generator
Generate cryptographically secure UUID v4 identifiers.
🔑 About UUIDs
Universally Unique Identifiers (UUIDs) are 128-bit values guaranteed to be unique across time and space. This generates UUID v4 (random) identifiers.
- Database primary keys
- API request tracking IDs
- Session identifiers
- File and resource naming
- Distributed system coordination
What are UUIDs?
Universally Unique Identifiers (UUIDs) are 128-bit values designed to be unique across time and space without requiring a central coordinating authority.
UUID v4 Structure
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
Length: 36 characters (32 hex + 4 hyphens)
Format: 8-4-4-4-12 hexadecimal digits
Version: 4 (random/pseudo-random)
Uniqueness: 2^122 possible values
Common Use Cases
Database Design
API Development
File Management
Microservices
Correlation IDs: Track requests across services
Event IDs: Unique event identification
Resource IDs: Distributed resource identification
Advantages Over Sequential IDs
| Aspect | UUID | Sequential ID |
|---|---|---|
| Uniqueness | Globally unique | Database unique only |
| Predictability | Unpredictable | Easily guessable |
| Distribution | Works offline | Requires coordination |
| Security | No information leakage | Reveals count/timing |
| Merging | No conflicts | Requires ID remapping |
Best Practices
Use for distributed systems
Store as UUID type in databases (not string)
Use for public APIs to prevent enumeration
Generate on client-side when possible
⚠️ Consider performance impact in high-frequency scenarios
⚠️ Not suitable for sorting by creation time
