How to generate UUIDs
- Pick the version and how many you need. New UUIDs appear right away.
- Turn on uppercase or turn off hyphens if your system needs that format.
- Copy them all, or download them as a text file with one UUID per line.
UUID v7 follows RFC 9562: the first 48 bits are the current time in milliseconds, the rest is random.
Questions
Should I use UUID v4 or v7?
Use v7 for database keys: it starts with a timestamp, so new IDs sort in creation order and keep indexes fast. Use v4 when the ID must not reveal when it was created.
Can two UUIDs ever be the same?
In practice, no. A v4 UUID has 122 random bits; you would need to create billions per second for many years before a duplicate becomes likely.
Is a GUID the same as a UUID?
Yes. GUID is Microsoft’s name for the same 128-bit identifier format.
Where do the random bits come from?
From your browser’s cryptographic random generator. Nothing is fetched from a server.
Credits
Built by OneTooling using standard browser features. No third-party code runs on your data.