UUID Generator

Free UUID generator: create random version 4 UUIDs (GUIDs) using crypto-secure randomness. Generate one or many at once.

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This tool has a free JSON API. Copy a prompt or skill below to use it with ChatGPT, Claude, or any AI agent — no API key needed.

API docs
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How uuid generator works

A UUID (Universally Unique Identifier), also known as a GUID, is a 128-bit identifier represented as 32 hexadecimal digits in five groups separated by hyphens, like 550e8400-e29b-41d4-a716-446655440000. UUIDs are designed to be globally unique without coordination between systems.

This generator creates version 4 UUIDs, which use random bytes for all 122 bits of variability. It uses the Web Crypto API (crypto.getRandomValues) for cryptographically secure randomness, making the UUIDs suitable for use as database keys, session tokens, and distributed system identifiers.

The probability of a collision is astronomically low: with 122 random bits, you would need to generate over 2.6 quintillion UUIDs before a 50% chance of collision. You can generate up to 100 UUIDs at once.

Frequently asked questions

What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hex digits in five hyphen-separated groups. Version 4 UUIDs use random bits, making collisions extremely unlikely.
Are the generated UUIDs unique?
Yes. Version 4 UUIDs use 122 bits of cryptographic randomness. The chance of two UUIDs colliding is so low it can be ignored for any practical purpose, even at massive scale.
What is the difference between UUID and GUID?
They are the same thing. GUID (Globally Unique Identifier) is the Microsoft term, while UUID is the RFC 4122 standard term. Both refer to the same 128-bit identifier format.
Is the randomness secure?
The generator uses the Web Crypto API (crypto.getRandomValues), which provides cryptographically secure random values. This is stronger than Math.random and suitable for security-sensitive identifiers.