UUID Generator
Generate unique identifiers (UUID/GUID) for applications and databases
UUID Settings
How many UUIDs to generate (1-1000)
Generated UUIDs
Quick Formats
Standard
xxxxxxxx-xxxx-xxxx
Uppercase
XXXXXXXX-XXXX-XXXX
No Hyphens
xxxxxxxxxxxxxxxx
Braced
{xxxxxxxx-xxxx}
Quoted
"xxxxxxxx-xxxx"
Bulk (100)
Multiple UUIDs
About UUIDs (Universally Unique Identifiers)
What is a UUID?
A UUID is a 128-bit identifier that is unique across both space and time. UUIDs are standardized by the Open Software Foundation (OSF) and are guaranteed to be unique without requiring a central authority.
UUID Versions
- UUID v4: Random/pseudo-random generation (recommended)
- UUID v1: Time-based with MAC address
- Nil UUID: All zeros (00000000-0000-0000-0000-000000000000)
Common Use Cases
- Database: Primary keys, foreign keys
- Web Development: Session IDs, API keys
- Distributed Systems: Node identification
- File Systems: Unique file naming
- Software: Component identification
- Testing: Test data generation
Format Variations
- Standard: 550e8400-e29b-41d4-a716-446655440000
- No Hyphens: 550e8400e29b41d4a716446655440000
- Braced: {550e8400-e29b-41d4-a716-446655440000}
- Uppercase: 550E8400-E29B-41D4-A716-446655440000
UUID Structure
A UUID consists of 32 hexadecimal digits displayed in five groups:
xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx
- M: Version (1, 3, 4, or 5)
- N: Variant (8, 9, A, or B)
Uniqueness Guarantee
- Probability: Collision chance is negligible
- Space: 2^128 possible values
- Time: Unique across time periods
- Global: No central authority needed
Technical Details
- Length: 36 characters (with hyphens)
- Encoding: Hexadecimal representation
- Generation: Cryptographically secure random
- Storage: 16 bytes in binary form
Best Practices
- Use UUID v4: For most applications
- Store efficiently: As binary in databases
- Index properly: Consider performance impact
- Validate format: Check structure before use