UUID Generator

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify information in distributed systems. UUIDs are designed to be unique across space and time without requiring a central authority.

Format

UUIDs follow the format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx

• 32 hexadecimal digits displayed in 5 groups separated by hyphens
• Total length: 36 characters (including hyphens)
• Version 4 UUIDs are randomly generated

Example: 550e8400-e29b-41d4-a716-446655440000

How to Use This Tool

Generate UUIDs

1. Set the Count field to how many UUIDs you need (1–50)
2. Click Generate to create random UUIDs
3. Each UUID appears in the list below with its own Copy button
4. Click Copy next to any UUID to copy it individually
5. Click Copy All to copy all UUIDs at once (newline-separated)
6. Use Clear to reset the list and start fresh

Typical Workflow

• Single UUID: Set count to 1, generate, copy
• Multiple UUIDs: Set count to desired number, generate, copy all for batch operations
• Quick regeneration: Generate, use some UUIDs, generate again without clearing

Common Use Cases

• Database Primary Keys: Use UUIDs as unique row identifiers instead of auto-increment integers
• API Request/Transaction IDs: Track requests across microservices and logs
• File/Object Names: Generate unique names for uploads, temp files, or cloud storage objects
• Session IDs: Create secure, unguessable session identifiers
• Distributed Systems: Generate IDs without coordination between servers
• Testing/Mocking: Create realistic test data with unique identifiers
• Message Queues: Assign unique IDs to messages for tracking and deduplication

UUID v4 Properties

• Randomness: Generated using cryptographically secure random numbers
• Collision Probability: Practically zero (1 in 2^122 for v4)
• No Sequential Pattern: Cannot predict next UUID from current one
• URL-Safe: Can be used in URLs without encoding
• No Central Registry: Generate anywhere without coordination

Tips

• Use UUIDs when uniqueness must be guaranteed across distributed systems
• For databases, consider indexing strategies—UUIDs are larger than integers (16 bytes vs 4–8 bytes)
• UUIDs are NOT cryptographic keys—don't use them for authentication or encryption
• Store UUIDs as binary (16 bytes) in databases for efficiency, not as strings (36 bytes)
• Version 4 (random) is the most common; other versions (v1, v5) use timestamps or namespaces