UUID Generator (v4 & v7)

A UUID (Universally Unique Identifier, also called a GUID) is a 128-bit label, usually written as 32 hexadecimal characters in five groups, like 3f2b8c1e-5d4a-4b7e-9c10-2a6f8e1d0b34. It lets different systems create IDs independently without coordinating and still avoid clashes.

Version 4 is made of 122 random bits. Version 7 starts with a 48-bit Unix timestamp in milliseconds followed by random bits, so v7 values sort in creation order, which is friendlier to database indexes. Both are defined in RFC 9562.

In theory yes, in practice no. With 122 random bits in a v4 UUID you would need to generate about 2.7 quintillion (2.7 × 10¹⁸) of them before there is even a 50% chance of a single duplicate.

A v4 UUID from a secure generator is unguessable, but UUIDs are designed as identifiers, not secrets, and are often logged or shown in URLs. For access tokens use the Random String Generator with at least 128 bits of entropy. Avoid v7 for anything secret, because it reveals when it was made.

No. They are generated in your browser and exist only on screen. Randomnumbers.co has no database and the page is blocked by your browser from contacting any other server.

Nothing meaningful. GUID (Globally Unique Identifier) is the name Microsoft uses; the format is the same. Microsoft tools often write GUIDs in uppercase inside braces, which this generator can do with the format options.