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UUID v4 Generator (Random)
Make random version 4 UUIDs with your browser's secure generator. Copy one or many.
📚 Official sources: UUID standard (RFC 9562)
We build every tool from the official rules and re-check them when they change. Always confirm with the official source before you rely on a result.
🛠️ Spotted a mistake or an out-of-date rule? Tell us
Questions people ask
What is the difference between UUID v4 and v7?+
v4 is fully random. v7 starts with the time it was created (in milliseconds) followed by random bits, so v7 IDs sort by creation time. That makes them faster as database primary keys.
Can two UUIDs ever be the same?+
In practice, no. A v4 UUID has 122 random bits: you would need to make billions every second for many years to have a real chance of a duplicate.
Is a GUID the same as a UUID?+
Yes. GUID is Microsoft's name for the same 128-bit identifier. Tick UPPERCASE and braces to get the {XXXXXXXX-…} style used in Windows and .NET.