UUID (Universally Unique Identifier) is a 128-bit identifier guaranteed to be unique across all devices and time. Format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.

What is the difference between UUID v1 and v4?

UUID v1 is based on timestamp and MAC address — it contains information about when and where it was created. UUID v4 is completely random — more private and more commonly used.

Are generated UUIDs truly unique?

UUID v4 has 122 random bits — the probability of generating two identical UUIDs is astronomically small. In practice they are considered unique.

What is a GUID?

GUID (Globally Unique Identifier) is Microsoft's term for UUID. They are the same thing — just different names used in different ecosystems.

Is my data safe?

Yes. UUIDs are generated entirely in your browser using the Web Crypto API. Nothing is sent to any server.