What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to identify information in computer systems. The term **GUID** (Globally Unique Identifier) is also often used, primarily in Microsoft systems, but they are effectively the same thing.
Because the probability of creating two identical UUIDs is incredibly low (negligible in practice), they are perfect for generating unique keys for database rows, sessions, or distributed systems without needing a central authority.
When to use UUIDs?
- Database Keys: When you need to merge records from different databases without conflicts.
- Session IDs: To track user sessions securely without predictive patterns.
- API Keys: As a component of secure tokens or temporary markers.
- Distributed Systems: When multiple independent systems need to generate IDs that must not collide.
Frequently Asked Questions
What version are these UUIDs?
This tool generates UUID Version 4 (randomly generated). This is the most common version used in modern web development.
Are they truly unique?
While not theoretically impossible, the collision probability of UUID v4 is so astronomically low that for all practical purposes, yes, they are unique. You would need to generate trillions of IDs per second for years to have a significant chance of a collision.
Can I generate UUIDs without hyphens?
Yes. Just uncheck the "Hyphens" box in the options panel, and the generator will produce the clean 32-character hexadecimal string.
Is it secure?
We use the browser's cryptographic API (`crypto.randomUUID`) when available, ensuring high-quality randomness suitable for most production use cases.