Quickly and easily generate individual or bulk sets of globally unique identifiers (GUIDs). What is a version 4 UUID? A Version 4 UUID is a universally unique identifier that is generated using random numbers. The Version 4 UUIDs produced by this site were generated using a secure random number generator. A Version 4 UUID is a universally unique identifier that is generated using random numbers. The UUIDs from this website were generated using a cryptographically-strong random number generator. Generate UUID/GUID identifiers instantly. Create version 1, 4, and nil UUIDs for databases, APIs, and applications. Free online UUID generator with bulk generation.