UUIDv4 Generator
Generate random version 4 UUIDs (Universally Unique Identifiers) instantly. Perfect for database keys, unique identifiers, and development testing.
đź’ˇ How to Use This Tool
Generate random UUIDs instantly with these simple steps:
Choose Quantity
Use the slider or dropdown to select how many UUIDs you need (1-50).
Set Format Options
Toggle uppercase letters or remove dashes based on your requirements.
Generate UUIDs
Click the Generate button to create your random UUIDs instantly.
Copy & Use
Copy individual UUIDs or all at once with a single click.
đź“– About UUIDv4 Generator
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is unique across space and time. UUIDs are standardized by the Open Software Foundation (OSF) and defined in RFC 4122.
UUID Version 4 (UUIDv4)
Version 4 UUIDs are randomly generated. They contain 122 random bits and 6 fixed bits that identify the version and variant. The format is:
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
Where:
xis any hexadecimal digit (0-9, a-f)4indicates this is a version 4 UUIDyis one of 8, 9, a, or b (variant bits)
Common Use Cases
- Database Primary Keys: Use UUIDs instead of auto-incrementing integers for distributed systems
- Session Identifiers: Generate unique session tokens for web applications
- File Names: Create unique file names to prevent collisions
- API Keys: Generate temporary or permanent API identifiers
- Distributed Systems: Ensure uniqueness across multiple servers without coordination
- Testing: Generate mock data with realistic unique identifiers
Why Use UUIDs?
Advantages
- Globally Unique: No central authority needed for generation
- Non-Sequential: Cannot be guessed or enumerated
- Mergeable: Easy to merge data from different sources
- Portable: Standard format works across all platforms
Collision Probability
The probability of generating two identical UUIDv4s is astronomically low—about 1 in 5.3 × 10^36. You would need to generate 1 billion UUIDs per second for 85 years to have a 50% chance of a collision.
Privacy & Security
This generator uses the Web Crypto API (crypto.randomUUID() or crypto.getRandomValues()) for cryptographically secure random number generation. All UUIDs are generated entirely in your browser—nothing is sent to any server.
âť“ Frequently Asked Questions
Version History
Initial release
Jan 24, 2026