What is a UUID?
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value used as a unique ID — for database records, API keys, session tokens, file names and more. This generator creates version 4 UUIDs (random), the most common type, using your browser’s cryptographically secure random source. Generate one or hundreds at once, all in your browser.
Frequently Asked Questions
Are these UUIDs really unique?
Version-4 UUIDs are random 122-bit values, so the chance of a collision is astronomically small — you’d need to generate billions before a duplicate becomes even remotely likely. They’re safe to use as unique IDs.
Are they generated securely?
Yes. They use the browser’s built-in crypto random source (the same one used for cryptographic keys), not the predictable Math.random(). Everything happens in your browser — nothing is sent anywhere.
What’s the difference between UUID and GUID?
They’re the same thing — GUID (Globally Unique Identifier) is Microsoft’s name for a UUID. The format is identical.
Can I get them without dashes or in uppercase?
Yes — tick “No dashes” for a compact 32-character string, or “Uppercase” if your system expects capitals. Both options work together.
