What is a UUID v4 and how is it generated?

A Version 4 UUID (Universally Unique Identifier) is a 128-bit identifier generated using cryptographically strong pseudo-random numbers conforming to RFC 4122 standard.

What is the difference between a UUID and a GUID?

UUID (Universally Unique Identifier) is the open IETF standard term, while GUID (Globally Unique Identifier) is Microsoft's implementation term. In modern software development, UUIDv4 and GUID are practically synonymous.

Are these UUIDs truly random and unique?

Yes. The generator uses the Web Cryptography API (crypto.getRandomValues), which provides cryptographically secure random numbers sourced from your operating system's entropy pool. The probability of generating duplicate UUID v4s is astronomically low — approximately 1 in 2^122.

Can I generate UUIDs in bulk?

Yes. You can generate up to 1,000 UUIDs at once. Each is generated using independent cryptographic randomness, ensuring uniqueness across the entire batch.

What UUID version does this generate?

This tool generates Version 4 (UUIDv4) identifiers, which are based on random numbers rather than timestamps or MAC addresses. UUIDv4 is the most widely used version in modern software development.

Do I need to be online to generate UUIDs?

No. After the initial page load, the generator works completely offline since it uses your browser's built-in cryptographic functions with no server dependency.

UUID / GUID Generator Online (UUIDv4 Bulk Generator)

What Is a UUID (Universally Unique Identifier)?

A UUID (Universally Unique Identifier), also known as a GUID, is a 128-bit value formatted as 32 hexadecimal digits separated by hyphens (e.g. `f47ac10b-58cc-4372-a567-0e02b2c3d479`). Version 4 UUIDs rely on cryptographically secure random numbers.

Cryptographic Randomness (Web Crypto API)

Unlike basic tools that rely on predictable `Math.random()`, OneToolBox uses the browser's native Web Crypto API (`crypto.getRandomValues`) to guarantee cryptographically secure randomness with near-zero collision probability.

UUID v4 Generator

What Is a UUID (Universally Unique Identifier)?

Cryptographic Randomness (Web Crypto API)

Related Tools

What Is UUID / GUID Generator?

How to Use UUID / GUID Generator

Frequently Asked Questions

Are these UUIDs truly random and unique?

Can I generate UUIDs in bulk?

What UUID version does this generate?

Do I need to be online to generate UUIDs?