Bulk Generation
• Randomly generated using cryptographically secure methods
• 122 bits of randomness
• No information about when or where it was generated
• Most commonly used UUID version
• Suitable for most applications
• Based on timestamp and MAC address
• Contains creation time information
• Guaranteed to be unique across space and time
• Can reveal information about the generator
• Less commonly used due to privacy concerns
Recently Generated UUIDs
Common Use Cases
Database Primary Keys
Use UUIDs as primary keys to avoid conflicts in distributed systems.
API Request IDs
Track API requests and responses with unique identifiers.
Session Tokens
Generate secure session identifiers for user authentication.
File Names
Create unique file names to prevent conflicts in storage systems.
About UUID Generation
Generate Universally Unique Identifiers (UUIDs) for databases, APIs, and applications. Our UUID generator supports both v1 (timestamp-based) and v4 (random) versions with bulk generation capabilities. Perfect for creating unique identifiers in distributed systems.
UUID Applications
- Database primary keys and foreign keys
- API request and response tracking
- Session tokens and authentication
- File naming and storage systems
Frequently Asked Questions
What's the difference between UUID v1 and UUID v4?
UUID v1 is timestamp-based and includes MAC address information, making it predictable but guaranteed unique across time and space. UUID v4 is randomly generated with 122 bits of randomness, providing better privacy but with a tiny collision risk. V4 is recommended for most applications.
How unique are UUIDs and can they collide?
UUID v4 has a collision probability of about 1 in 5.3 x 10^36 for each pair. You'd need to generate billions of UUIDs per second for thousands of years to have a reasonable chance of collision. For practical purposes, UUIDs are considered globally unique.
Should I use UUIDs as database primary keys?
UUIDs work well as primary keys in distributed systems, preventing conflicts during data merging. However, they're larger than integers (16 bytes vs 4-8 bytes) and can impact performance. Consider your specific use case - UUIDs excel in distributed systems, while integers are better for single-database applications.
Can I use UUIDs for security tokens or session IDs?
UUID v4 provides good randomness for session tokens and non-critical security applications. However, for high-security tokens like API keys or authentication tokens, use cryptographically secure random generators specifically designed for security purposes rather than general-purpose UUIDs.
What are the common use cases for UUIDs?
UUIDs are ideal for distributed database primary keys, API request tracking, file naming, session identifiers, message queuing, microservices communication, and any scenario requiring globally unique identifiers without central coordination.