UUID Generator
Generate various types of UUIDs (Universally Unique Identifiers) for your applications. Choose from different versions based on your specific needs.
UUID v4 (Random)
Generate random UUIDs using cryptographically strong random values. Perfect for most use cases where you need unique identifiers without revealing any information about the time or location of generation.
Bulk Generation
Generate multiple UUIDs at once for batch operations
Only 1 to 10,000 allowed
API Information
Use these endpoints to integrate UUID generation into your applications
https://fastweb.tools/api/uuid/v4Generate a single v4 UUID
https://fastweb.tools/api/uuid/v4?count=100Generate multiple v4 UUIDs (max: 10,000)
What is UUID v4? Random
UUID v4 (version 4) is a randomly generated UUID that uses cryptographically strong random or pseudo-random numbers. It provides excellent uniqueness without revealing any information about the generating system or timestamp.
Structure:
- Random bits: 122 bits of random/pseudo-random data
- Version: 4 bits set to '0100' (version 4)
- Variant: 2 bits set to '10' (RFC 4122 variant)
Example Format:
f47ac10b-58cc-4372-a567-0e02b2c3d479Collision Probability:
The probability of generating duplicate UUIDs is negligibly small (approximately 1 in 5.3 x 10³⁶ for two UUIDs).
When to Use UUID v4
✅ Perfect For:
- General-purpose unique identifiers
- Privacy-sensitive applications
- Security tokens and session IDs
- API keys and reference numbers
- Distributed systems without central coordination
- Most web applications and services
⚠️ Consider Alternatives When:
- Database performance is critical (consider v7)
- Natural sorting by creation time needed (use v1, v6, or v7)
- Extremely high-frequency generation (consider v7)
Performance:
Excellent generation performance with minimal overhead. Only requires access to a good random number generator.
Technical Details & Best Practices
Security
Cryptographically secure with no predictable patterns. Safe for security-sensitive applications and public exposure.
Privacy
Reveals no information about the generating system, location, or time. Ideal for privacy-conscious applications.
Database Indexing
Random nature can cause index fragmentation in databases. Consider using as secondary key rather than primary key.
Implementation Notes
UUID v4 is the most widely supported and used UUID version. It's the default choice for most applications due to its simplicity, security, and privacy benefits. The only trade-off is potential database performance impact due to randomness, but this is often negligible for most applications.