What is a UUID v4?
A UUID is a 128-bit identifier written in a standard hexadecimal format. Version 4 UUIDs are random, making collisions extremely unlikely when generated with a secure random source. They are commonly used as database keys, request IDs and file identifiers.
Are these UUIDs globally guaranteed to be unique?
No random system can provide an absolute guarantee, but properly generated UUID v4 values have an extremely low collision probability.
Where are UUIDs generated?
This page uses the browser cryptography API; UUIDs are not requested from a server.