ToolsYard

UUID Generator

Choose how many you need and generate random version 4 UUIDs.

What this tool does

This tool generates random version 4 UUIDs (universally unique identifiers, also called GUIDs) using your browser's cryptographically secure random number generator. A version 4 UUID is a 128-bit value formatted as 32 hex digits in five groups — for example 3fa85f64-5717-4562-b3fc-2c963f66afa6 — with a fixed version and variant bit pattern that makes it statistically unique across any system, anywhere, without needing a central registry. Generation happens entirely in your browser; nothing is sent anywhere.

Example use case

Developers use UUIDs as primary keys in databases, unique IDs for API resources, session tokens, or correlation IDs for tracing a request across distributed services. Generating a batch at once is handy when seeding test data or writing example records that each need a distinct identifier.

Uppercase and hyphens

UUIDs are conventionally lowercase with hyphens separating the five groups, but some systems and legacy APIs expect uppercase hex digits or a hyphen-free 32-character string. The options above let you match whichever format your target system requires without manual find-and-replace.