Just File Tools

UUID Generator

Generate random UUID/GUID values

How to uuid generator online

Generate cryptographically random UUID v4 values for use in databases, APIs, and applications.

  1. Click "Generate UUID" to create a single random UUID.
  2. Click the "Copy" button to copy the UUID to your clipboard.
  3. For multiple UUIDs, enter a count (1-100) in the bulk generate section.
  4. Click "Generate N UUIDs" to create multiple values at once.
  5. Click "Copy All" to copy all generated UUIDs to your clipboard, one per line.

About UUID Generator

UUIDs (Universally Unique Identifiers), also known as GUIDs (Globally Unique Identifiers), are 128-bit identifiers used throughout software development to uniquely identify records, resources, and entities without relying on a centralized numbering authority. They are essential for distributed systems, database primary keys, API request tracking, session identifiers, and anywhere you need a guaranteed-unique value.

This tool generates version 4 UUIDs, which are based entirely on random numbers. It uses the browser's built-in crypto.randomUUID() API, which produces cryptographically secure random values. Version 4 is the most widely used UUID version because it requires no input data (no MAC address, no timestamp) and can be generated independently by any system with a good random number generator.

The bulk generation feature lets you create up to 100 UUIDs at once, which is handy for seeding test databases, generating configuration files, or pre-allocating identifiers for batch operations. All generation happens locally in your browser — no server is involved, and no UUIDs are logged or stored anywhere.

Frequently Asked Questions

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hexadecimal digits in five groups separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000). UUIDs are designed to be globally unique without requiring a central authority.

What version of UUID does this generate?

This tool generates version 4 UUIDs, which are created using cryptographically secure random numbers via the browser's crypto.randomUUID() API. Version 4 UUIDs are the most commonly used type.

Are the generated UUIDs truly unique?

Version 4 UUIDs have 122 random bits, giving approximately 5.3 x 10^36 possible values. The probability of generating a duplicate is astronomically small — effectively zero for any practical use case.

Can I generate multiple UUIDs at once?

Yes. Use the "Bulk Generate" option to create up to 100 UUIDs at once. You can copy all of them to your clipboard with a single click.