Online UUID / GUID Generator

A UUID (Universally Unique Identifier) is a 128-bit value used as an identifier that's practically guaranteed not to collide with any other UUID, generated by anyone, anywhere, without a central coordinating authority. This tool generates version-4 (random) UUIDs using your browser's cryptographically secure random number generator.

Features:

• Bulk generation: Generate up to 200 UUIDs at once.
• Format options: Standard hyphenated, no hyphens, uppercase, or wrapped in braces.
• Cryptographically secure: Uses crypto.randomUUID(), not Math.random().

1. What a UUID Looks Like

A standard UUID looks like f47ac10b-58cc-4372-a567-0e02b2c3d479 — 32 hexadecimal digits grouped as 8-4-4-4-12. The "4" in the third group marks this as version 4 (randomly generated), the most common variant and the one this tool produces.

2. Common Uses

• Database primary keys: avoids collisions across distributed systems without a central counter
• API request IDs: trace a single request through logs across multiple services
• File and session identifiers: generate a unique name with no lookup required
• Test fixtures: generate placeholder IDs that won't clash with real data