What is a UUID?

A UUID (Universally Unique Identifier), also known as a GUID (Globally Unique Identifier), is a 128-bit number used to identify information in computer systems. The term universally unique means that the probability of generating the same UUID twice is virtually zero, even without a central coordination authority.

Version 4 vs Version 1 UUIDs

There are several versions of UUIDs, but the most common are Version 1 and Version 4:

• Version 1: Generated using the timestamp and the computer's MAC address. It is unique but can reveal the time and location of creation.
• Version 4: Generated using random numbers. This is the most popular version for general use (and the one this tool generates) because it provides a high degree of randomness and privacy.

Common Use Cases

Developers use UUIDs for database primary keys, session IDs, transaction tracking, and identifying temporary files. Because they don't require a central server to ensure uniqueness, they are perfect for distributed systems and microservices.