UUID Generator
Generate one or more random UUID v4 values (also called GUIDs) — useful as unique IDs in databases, filenames, or test data.
How to use the UUID generator
- Choose how many UUIDs you need (1–100).
- Press "Generate new" to create new random values.
- Press "Copy all" to put the list on your clipboard.
What is a UUID v4?
A UUID (Universally Unique Identifier) is a 128-bit value written as 32 hexadecimal characters in the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. Version 4 means the value is generated randomly (unlike, for example, version 1, which is based on timestamp and machine ID). The probability of two randomly generated UUID v4s colliding is so low it can be ignored in practice — even with billions of generated IDs.
UUIDs are often used as database primary keys, unique filenames, session IDs, and test data, precisely because they can be generated independently (e.g. on different servers) without risk of two systems producing the same ID.
Frequently asked questions
Are the UUIDs guaranteed to be unique?
Not mathematically guaranteed, but practically unique — the probability of collision is so extremely low (around 1 in 2.7 × 10^18 even with billions of IDs) that it isn't a real concern in practice.
Are the UUIDs sent to a server?
No. All values are generated directly in your own browser and aren't stored or sent anywhere.
What's the difference between UUID and GUID?
In practice they're the same thing — GUID (Globally Unique Identifier) is Microsoft's name for the same concept defined by the UUID standard.