UUID Generator

Generate UUID v4 (Universally Unique Identifier) strings instantly. Perfect for database keys, session IDs, and unique identifiers.

Generate UUIDs

c13840a9-b5bc-4323-8d76-dc43ce3381a2

UUID Formats & Examples

Standard Format (with hyphens)

550e8400-e29b-41d4-a716-446655440000

Compact Format (without hyphens)

550e8400e29b41d4a716446655440000

Remove hyphens manually if needed for your application

UUID v4 Structure

• 32 hexadecimal characters (128 bits)
• Version 4: Random or pseudo-random generation
• Format: 8-4-4-4-12 (with hyphens)
• Probability of collision: ~5.3 × 10⁻³⁶

About UUIDs

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier that is guaranteed to be unique across all systems and time. UUIDs are commonly used in software development for database primary keys, session identifiers, and distributed systems.

Our generator creates UUID v4, which uses random or pseudo-random numbers to ensure uniqueness with extremely low probability of collision.

UUID Format

UUIDs are typically displayed as 32 hexadecimal digits in groups separated by hyphens:

xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx

The "4" indicates version 4, and "y" is one of 8, 9, A, or B.

Common Use Cases

Database Keys

Primary keys for database tables that need to be unique across different systems.

Session IDs

Secure session identifiers for web applications and API authentication.

Distributed Systems

Unique identifiers that work across multiple servers and applications.

Frequently Asked Questions

What is a UUID and why would I need one?
A UUID (Universally Unique Identifier) is a 128-bit identifier guaranteed to be unique across all systems and time. They're essential for database primary keys, session IDs, API keys, file naming, and distributed systems where uniqueness is critical without central coordination.
Are UUIDs truly unique and collision-free?
UUID v4 (which our generator creates) has an extremely low probability of collision - approximately 1 in 5.3 x 10^36. While theoretically possible, collisions are so statistically unlikely that UUIDs are considered practically unique for all real-world applications.
What's the difference between UUID versions?
Our generator creates UUID v4 (random), which uses random or pseudo-random numbers. Other versions include v1 (timestamp + MAC address), v3 (MD5 hash), and v5 (SHA-1 hash). V4 is most common for general use due to privacy and simplicity.
Can I use UUIDs as database primary keys?
Yes, UUIDs make excellent primary keys, especially in distributed systems or when merging databases. They're globally unique, don't reveal information about record count, and prevent conflicts when replicating data across systems. However, they're larger than sequential integers.
How many UUIDs can I generate safely?
You can generate billions of UUIDs without practical concern for collisions. Even generating one billion UUIDs per second for 100 years would still have an astronomically low collision probability. Our generator has no limits - create as many as you need.
Is UUID generation secure and private?
Yes, our UUID generation happens entirely in your browser using cryptographically secure random number generation. No data is sent to servers, and generated UUIDs contain no personal information or patterns that could be traced back to you or your system.