UUID Generator

A UUID (Universally Unique Identifier), also known as a GUID (Globally Unique Identifier), is a 128-bit identifier standardized in RFC 4122. It is formatted as 32 hexadecimal digits in five groups: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.

This tool generates UUID version 4, which is based on random numbers. The version (4) and variant bits are fixed, and the remaining 122 bits are randomly generated. With 2^122 possible values (approximately 5.3 × 10^36), UUID v4 collisions are essentially impossible in practice.

UUIDs are used everywhere in software: as primary keys in databases (avoiding the need for sequential IDs), unique identifiers for API resources, distributed system correlation IDs, session tokens, file names in object storage, and anywhere a unique ID is needed without central coordination.

This tool uses crypto.randomUUID() — the browser's built-in UUID v4 generator, available in all modern browsers. As a fallback for older browsers, it uses crypto.getRandomValues() with the same cryptographic quality. Both methods use the operating system's cryptographically secure random number generator.

Nothing is sent to any server. All UUIDs are generated locally in your browser. You can generate up to 100 UUIDs at once, copy them individually, or copy all in one click as a newline-separated list.

You may also find our Random String Generator, Hash Generator, and Password Generator helpful.