UUID / GUID Generator

Quick start

How to use UUID / GUID Generator

1. 1

   Select the quantity of UUIDs you wish to generate at once.

2. 2

   Choose optional representation settings such as uppercase output or removing hyphens.

3. 3

   Click "Generate New" to create a fresh batch of Version-4 identifiers.

4. 4

   Copy an individual UUID, copy the complete batch, or download the results as TXT or JSON.

Overview

About UUID / GUID Generator

A UUID (Universally Unique Identifier) or GUID (Globally Unique Identifier) is a 128-bit identifier represented as a string of 32 hexadecimal characters grouped into five sections separated by hyphens (8-4-4-4-12). UUIDs are common in database design, distributed systems, APIs, and event-driven applications. They allow developers to create identifiers across independent systems without coordinating a central sequential counter. A UUID is an identifier, not automatically an authentication secret or access token. Our Free Online UUID / GUID Generator produces Version-4 UUIDs directly inside your browser using cryptographically strong browser randomness. A UUID v4 contains 122 random bits after the version and variant bits are set, giving an extremely large identifier space. The tool can generate one or many identifiers for testing, database seeding, request correlation, and similar development workflows.

FAQ

Frequently asked questions

Are generated UUIDs truly unique?

UUID v4 does not provide a mathematical uniqueness guarantee, but it contains 122 random bits in the standard layout. With a cryptographically strong random source, collision probability remains extremely low for ordinary application volumes, though it increases as more identifiers are generated.

What is the difference between a UUID and a GUID?

GUID is Microsoft terminology commonly used for 128-bit identifiers that are generally compatible with the familiar UUID textual form. Modern UUID definitions are standardized in RFC 9562, which replaced RFC 4122.

What makes Version 4 UUIDs different from Version 1 or Version 5?

Version 4 UUIDs are completely randomized using cryptographic random numbers. Version 1 uses timestamp data and MAC address info, while Version 3 and Version 5 use namespace hashing with MD5 or SHA-1 algorithms.

Are generated UUIDs logged or stored on your backend servers?

UUID generation itself runs in your browser and does not require sending the generated identifiers to our application server. Site-level analytics and advertising are described separately in the Privacy Policy.