UUID / GUID Generator

Generate secure, cryptographically random UUIDs/GUIDs in bulk offline instantly.

Generator Options

UUID Version

Identifier Version

Generation Rules

Quantity to Generate

Output Case Casing

Include Standard Hyphens

Wrap in Curly Braces { }

Custom Entry Separator

Generated Identifiers

0 entries

What is a UUID (GUID) and how are they used?

A **UUID (Universally Unique Identifier)**, also known as a **GUID (Globally Unique Identifier)** in Microsoft ecosystems, is a 128-bit label used to uniquely identify information in computer systems. Standard UUIDs consist of 32 hexadecimal digits displayed in 5 groups separated by hyphens (format: `8-4-4-4-12` like `123e4567-e89b-12d3-a456-426614174000`).

Because UUIDs are mathematically guaranteed to be unique across space and time without requiring a centralized registration authority, they are extensively used as primary keys in distributed databases, session identifiers, file filenames, and transaction trace IDs.

Frequently Asked Questions (FAQ)

What are the differences between UUID Versions?

- **Version 4**: Uses cryptographically secure pseudo-random bytes. It is the most common format because it does not depend on system state. - **Version 7**: Embeds a 48-bit Unix millisecond timestamp at the beginning of the UUID, followed by random bits. This preserves database index sorting performance because generated IDs naturally increase sequentially. - **Version 1**: Generates IDs based on a high-precision timestamp, clock sequence, and the host's MAC address (simulated securely here using random bytes to prevent tracking).

Are these UUIDs secure and safe to use?

Yes. The generator utilizes the native browser Web Crypto API (`window.crypto.getRandomValues`) to draw secure, unpredictable random numbers. The execution is client-side, meaning no identifiers are transmitted or logged, ensuring full security.

What is the probability of a UUID collision?

For UUID v4, the collision risk is practically zero. You would need to generate 1 billion UUIDs every second for about 85 years to have a 50% chance of a single duplicate.