UUID / GUID Generator

Using the UUID/GUID Generator

This is a simple one-click tool to generate one or more Version 4 universally unique identifiers (UUIDs).

  1. Set the Amount: Enter the number of UUIDs you wish to create.
  2. Generate: Click the "Generate" button.
  3. Copy the Result: Click the "Copy" button to copy all the generated UUIDs to your clipboard, each on a new line.

What is a UUID or GUID?

A UUID (Universally Unique Identifier), also commonly known as a GUID (Globally Unique Identifier), is a 128-bit number used to identify information in computer systems. The term GUID is typically used in the context of Microsoft technologies.

The key feature of a UUID is that it is, for all practical purposes, unique. The probability of two independently generated UUIDs being the same is so infinitesimally small that it is considered negligible. This makes them useful in distributed systems where multiple developers or servers need to create identifiers without needing to coordinate with a central authority.

Version 4 UUIDs

There are several versions of UUIDs, each with a different generation method. This generator creates Version 4 (v4) UUIDs, which are the most common type. A v4 UUID is generated using random or pseudo-random numbers. This tool uses the browser's crypto.getRandomValues API, which provides a cryptographically strong source of randomness.

A v4 UUID has a specific format, for example: 123e4567-e89b-42d3-a456-556642440000. The "4" at the beginning of the third group signifies that it is a Version 4 UUID.

Common Use Cases for Developers

UUIDs are a fundamental tool in software development, particularly for:

  • Database Primary Keys: Using UUIDs as primary keys for database records allows you to generate IDs on the application server rather than relying on the database's auto-incrementing feature. This is especially useful in distributed or offline-first applications.
  • Transaction IDs: Assigning a unique UUID to every transaction or request in a system (e.g., an API call or a logging event) makes it easy to track and debug.
  • Component Keys in Front-End Frameworks: In libraries like React, when you render a list of items, each item needs a unique key prop. UUIDs are a perfect way to generate these keys for dynamically created, non-persistent items.
  • Naming Temporary Files: Generating a UUID for a temporary filename ensures that it will not conflict with any other file.