UUID Generator

What Is a UUID Generator?

A UUID generator creates Universally Unique Identifiers, commonly known as UUIDs or GUIDs. A UUID is a 128-bit identifier normally represented as 32 hexadecimal characters separated into groups by hyphens. UUIDs are widely used to identify records, resources, objects, transactions and other data in software systems.

This free UUID Generator creates random version 4 UUIDs directly in your browser. You can generate a single UUID or a batch of up to 100 UUIDs and copy the resulting values for use in applications, databases, development projects and testing.

Why Use UUID Generator?

Generating UUIDs manually is unnecessary and prone to formatting mistakes. This tool provides correctly structured random version 4 UUIDs on demand, while using your browser's secure random number facilities to produce the random portions.

How to Use the UUID Generator

Generating UUIDs takes only a few seconds. Select the number of identifiers you need and generate them instantly.

1. Choose the number of UUIDs — Select between 1 and 100 UUIDs from the Number of UUIDs menu.
2. Generate the UUIDs — Click Generate UUIDs to create random version 4 UUIDs.
3. Review the results — Each generated UUID appears on its own line in the results box.
4. Copy the UUIDs — Click Copy All to copy every generated UUID to your clipboard, or select individual values manually.

Generate Random UUIDs Online

UUIDs are useful when software needs identifiers that can be generated independently without relying on a central numbering service. A version 4 UUID contains randomly generated data together with bits that identify its version and variant. The conventional textual representation contains 36 characters, including four hyphens.

Because version 4 UUIDs have an extremely large number of possible combinations, correctly generated values have a very low probability of accidentally colliding. This makes them useful in distributed systems and applications where multiple components may need to create identifiers independently.

How UUID Version 4 Works

A version 4 UUID is based primarily on random data. Certain bits are reserved for the UUID version and variant, so those positions are set to their required values while the remaining bits are supplied by a secure random source. The result is represented in the familiar hexadecimal UUID format.

Common Uses for UUIDs

UUIDs are commonly used for database record identifiers, application objects, resources, transactions, events, files, distributed-system references and test data. They can be especially useful when identifiers need to be generated independently across different servers, applications or processes.

UUID Generator Security and Limitations

This UUID Generator uses the browser's Web Crypto API to obtain cryptographically strong random values. It does not use Math.random() for UUID generation and does not silently fall back to a weaker random source if the required Web Crypto functionality is unavailable.

Generated UUIDs are processed locally in your browser and are not sent to YesTools for generation or storage. Although version 4 UUIDs are designed to make accidental collisions extremely unlikely, UUIDs should not automatically be treated as secret credentials, authentication tokens or encryption keys.

UUIDs provide probabilistic uniqueness rather than an absolute guarantee that two independently generated values can never be identical. Applications with specialised identifier requirements should follow the identifier and database recommendations appropriate to their particular system.

Frequently Asked Questions