A 128-bit universally unique identifier generated from cryptographically random data, formatted as 8-4-4-4-12 hexadecimal digits.

Are UUID v4 collisions possible?

Practically no — 122 random bits make collisions negligible at any realistic scale.

UUID v4 Generator — Bulk Random GUIDs

UUID v4 Generator

Generate one or hundreds of version-4 UUIDs using your browser’s cryptographic random number generator. Nothing is transmitted — every identifier is created locally.

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Generated UUIDs

What is a UUID v4?

A UUID (Universally Unique Identifier, also called GUID) is a 128-bit identifier written as 32 hexadecimal digits in five groups: 8-4-4-4-12. Version 4 UUIDs are generated from random data — with 122 random bits, the chance of two ever colliding is negligible for practical purposes.

This tool uses crypto.getRandomValues (or the native crypto.randomUUID when available), the same cryptographically secure source browsers use for security features — not the weaker Math.random().

Frequently Asked Questions (FAQ)

Q: Are these UUIDs really unique?

A: Statistically yes: you would need to generate about 2.7 quintillion UUIDs to reach a 50% chance of a single collision.

Q: Can UUIDs be used as database primary keys?

A: Yes, commonly. Note that random UUIDs can fragment clustered indexes; some databases prefer sequential variants (UUID v7) for high-insert tables.

Q: Is this generator secure?

A: It uses the browser’s cryptographically secure random source, generated locally on your machine.