UUID Generator — Free Online v4 UUID Tool

Generate cryptographically random version 4 UUIDs (RFC 4122). Choose how many you need, toggle case, hyphens, and braces, then copy them all at once.

• Bulk generation, up to 1000 at once
• Uppercase / lowercase toggle
• With or without hyphens
• Optional braces (e.g. for Windows GUID format)
• Copy-to-clipboard, one per line

A Universally Unique Identifier: a 128-bit value used to identify information without requiring a central authority to avoid collisions. Version 4 UUIDs are generated from random bits, making accidental collisions astronomically unlikely.

Each is generated using your browser's cryptographically secure random number generator (Web Crypto API), the same source used for encryption keys. The chance of two colliding is effectively zero.

Yes. V4 UUIDs generated this way are suitable as primary keys, correlation IDs, or API tokens. Nothing is sent to a server — generation happens entirely in your browser.

GUID (Globally Unique Identifier) is Microsoft's name for the same concept. They're structurally identical to UUIDs; GUIDs are sometimes formatted with surrounding braces, which this tool supports.