UUID Generator

Generate universally unique identifiers (UUIDs/GUIDs) in bulk. Support for Version 1 (Time-based) and Version 4 (Random).

Generated UUIDs (0)

What is a UUID (Universally Unique Identifier)?

A UUID (Universally Unique Identifier) is a 128-bit number used to identify information in computer systems. When generated according to the standard methods, UUIDs are, for practical purposes, unique. Their uniqueness does not depend on a central registration authority or coordination between the parties generating them.

A UUID is written as a sequence of 32 hexadecimal digits separated by hyphens into five groups (8-4-4-4-12), resulting in a total of 36 characters (e.g., 123e4567-e89b-12d3-a456-426614174000).

UUID Versions Explained

There are several versions of UUIDs, each generated using different algorithms:

  • Version 1 (Time-based): Generated using the current time and the MAC address of the computer generating it. This guarantees uniqueness across space and time but can expose the identity of the generating machine.
  • Version 4 (Random): The most common type. Version 4 UUIDs are generated entirely randomly. The number of possible v4 UUIDs is so incredibly large (2122) that the probability of generating two identical UUIDs (a collision) is essentially zero.

Common Use Cases

  • Database Keys: Used as primary keys in distributed databases where auto-incrementing integers are impractical.
  • Session IDs: Generating unique identifiers for user sessions in web applications.
  • File Names: Ensuring uploaded files have globally unique names to prevent overwrites.
  • Distributed Systems: Tracking transactions or messages across microservices.