UUID generator
Generate cryptographically-random version-4 UUIDs (GUIDs) in bulk. Choose how many, then copy them all or download them as a text file. They're created in your browser with the Web Crypto API, so nothing is sent anywhere.
How to generate UUIDs
- Pick how many UUIDs you need with the slider.
- They're generated instantly; toggle uppercase or remove the hyphens if you prefer.
- Copy them all or download a .txt file. Click Generate any time for a fresh set.
About UUIDs
Version-4 UUIDs are the go-to way to create unique identifiers without a central authority: primary keys, idempotency keys, request IDs, file and object names, and correlation IDs across services. Because they're random, any number of machines can generate them at once without ever coordinating, and the chance of two matching is vanishingly small.
This generator uses the browser's cryptographically-secure random source, makes as many as you need at once, and lets you copy or download the whole batch. It all runs client-side, so the identifiers never travel over the network before you use them.
Frequently asked questions
What is a version-4 UUID?
A UUID is a 128-bit identifier written as 32 hexadecimal digits in the familiar 8-4-4-4-12 pattern. Version 4 fills 122 of those bits with random data (the rest encode the version and variant), so two generated values practically never collide — which is why UUIDs are used as database keys and unique identifiers without any central coordination.
Are these UUIDs secure and random?
Yes. They're generated with the browser's Web Crypto API (crypto.randomUUID, with a secure getRandomValues fallback), which is a cryptographically-secure random source — never the predictable Math.random.
What's the difference between a UUID and a GUID?
Nothing meaningful — they're the same 128-bit identifier. GUID is the name Microsoft uses; UUID is the term in the RFC standard. The values are interchangeable.
Is anything sent to a server?
No. Every UUID is generated locally in your browser; nothing is requested from or sent to a server.