Free UUID Generator Online
Generate random UUIDs, GUIDs, and unique identifiers instantly. Support for UUID v1, v4, v5, v6 with bulk generation, multiple output formats, and instant copy. No registration required.
UUID Generator
Generated UUID
About UUIDs
A Universally Unique Identifier (UUID) is a 128-bit identifier used to uniquely identify information in computer systems. UUIDs are designed to be unique across space and time without requiring a central authority.
The standard UUID format consists of 32 hexadecimal digits displayed in five groups separated by hyphens: 8-4-4-4-12 for a total of 36 characters.
UUID Versions
UUID v1 - Time-based
Generated using timestamp and MAC address. Provides time ordering but may reveal information about the generating system.
UUID v4 - Random
Generated using random or pseudo-random numbers. Most commonly used version for general purposes.
UUID v5 - Name-based
Generated using SHA-1 hash of a namespace and name. Deterministic - same input always produces same UUID.
Common Use Cases
Database Primary Keys
Use UUID v4 for distributed database primary keys that need to be unique across systems without coordination.
API Request IDs
Track API requests and responses using UUIDs for correlation across microservices and logging systems.
File and Resource Names
Generate unique filenames and resource identifiers to prevent naming conflicts in distributed systems.
Output Formats
| Format | Example | Use Case |
|---|---|---|
| Standard | 550e8400-e29b-41d4-a716-446655440000 | Most common format |
| No Hyphens | 550e8400e29b41d4a716446655440000 | Compact representation |
| Braces | {550e8400-e29b-41d4-a716-446655440000} | Microsoft GUID format |
| URN | urn:uuid:550e8400-e29b-41d4-a716-446655440000 | RFC 4122 URN format |
Tips and Best Practices
Security Considerations
- • Use UUID v4 for security-sensitive applications
- • Avoid UUID v1 if MAC address privacy is a concern
- • UUID v5 is deterministic - same input = same output
- • UUIDs are not cryptographically secure tokens
Performance Tips
- • UUID v4 has better randomness distribution
- • Consider UUID v6 for time-ordered database keys
- • Store UUIDs as binary in databases when possible
- • Use appropriate indexing strategies for UUID columns
Frequently Asked Questions (FAQ)
What is the difference between UUID and GUID?
UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are essentially the same thing. GUID is Microsoft's term for UUID. Both follow the same RFC 4122 standard and have identical structure and format.
Which UUID version should I use?
For most applications, use UUID v4 (random). It provides excellent uniqueness without revealing system information. Use UUID v1 if you need time-ordering, UUID v5 for deterministic generation from names, and UUID v6 for database-friendly time-ordered keys.
Are UUIDs truly unique?
While theoretically possible, UUID collisions are extremely rare. UUID v4 has 2^122 possible values (about 5.3 × 10^36), making the probability of collision negligible for practical purposes. The chance of generating duplicate UUIDs is astronomically small.
Can I use UUIDs as database primary keys?
Yes, UUIDs make excellent primary keys for distributed systems. They eliminate the need for centralized ID generation and prevent conflicts when merging databases. However, consider using UUID v6 or storing as binary for better database performance.
Is this UUID generator free to use?
Yes, this UUID generator is completely free to use with no registration required. All generation happens locally in your browser, ensuring privacy and speed. You can generate unlimited UUIDs for personal or commercial use.
Why Choose Our UUID Generator?
🚀 Fast & Reliable
Generate UUIDs instantly with our optimized algorithms. No server delays - everything runs locally in your browser for maximum speed and reliability.
🔒 Privacy First
Your data never leaves your browser. All UUID generation happens client-side, ensuring complete privacy and security for your projects.
📱 Mobile Friendly
Responsive design works perfectly on desktop, tablet, and mobile devices. Generate UUIDs anywhere, anytime, on any device.
🎯 Multiple Formats
Support for standard, uppercase, no-hyphens, braces, and URN formats. Get UUIDs in exactly the format you need for your application.
⚡ Bulk Generation
Generate up to 1000 UUIDs at once with our bulk generation feature. Perfect for database seeding, testing, and large-scale applications.
📋 Easy Copy & Export
One-click copy to clipboard and file download options. Seamlessly integrate generated UUIDs into your development workflow.