UUID Generator
Generate UUID v4 Online - Random UUID Generator
Generate random UUIDs (version 4) instantly. Create one or multiple UUIDs at once with options for different formats. This secure UUID generator uses cryptographically secure random number generation.
Runs entirely in your browser - no data is sent to any server.
4d494c12-aa50-4e67-a735-3ab5c4defbe8UUID v4 Format Explained
The UUID v4 structure is 32 hexadecimal digits in 5 groups separated by hyphens (8-4-4-4-12). The "4" indicates version 4 (random), and "y" is one of 8, 9, a, or b (variant indicator).
Example: 550e8400-e29b-41d4-a716-446655440000
UUID v4 vs Other Versions
Generated from random/pseudo-random numbers. Most common choice.
Based on timestamp and MAC address. Can reveal creation time.
Deterministic from namespace and name using SHA-1.
Common UUID Uses
- ->Database primary keys: Unique IDs without coordination
- ->Session tokens: Secure user session identification
- ->Distributed systems: IDs across multiple services
- ->API request tracking: Correlate logs across systems
Frequently Asked Questions
What is UUID v4?
UUID v4 is a randomly generated universally unique identifier. Unlike v1 (timestamp-based), v4 UUIDs use random numbers, making them unpredictable and ideal for security-sensitive applications.
Are UUIDs truly unique?
Practically yes. With 122 random bits (5.3 x 10^36 possibilities), the chance of collision is astronomically small. You'd need to generate 1 billion UUIDs per second for 85 years to have a 50% collision chance.
Can UUIDs be used as database keys?
Yes, UUIDs are commonly used as primary keys in distributed systems. They're larger than auto-increment integers (16 bytes vs 4-8) but allow ID generation without central coordination.