Generating unique identifiers is a common task in web development. Whether you're creating temporary IDs, identifying records, or preparing sample data, UUIDs can help.

The good news? Modern JavaScript can generate UUIDs without installing an external library.

In this tutorial, you'll learn how to use crypto.randomUUID() , understand when it works, and handle common errors.

1. What Is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier commonly represented as 32 hexadecimal characters separated by hyphens.

Here's an example of a UUID v4:

550e8400-e29b-41d4-a716-446655440000

Enter fullscreen mode

Exit fullscreen mode

UUIDs are commonly used for:

Identifying application records

Generating test data

Tracking objects across systems

Creating identifiers for distributed applications

Assigning unique references to resources

UUIDs are designed to make accidental collisions extremely unlikely, but uniqueness is not mathematically guaranteed.

2.…