UUID Generator

How to use it

1. 1Pick v4 for a plain random identifier, or v7 if the values will be a database primary key.
2. 2Set how many you need and press generate.
3. 3Copy them all at once with the copy button above the list.
4. 4Paste any UUID into the inspect box below to check it is valid and see its version.
5. 5Press generate again for a fresh batch — nothing is stored, and reloading discards them.

Frequently asked questions

Should I use v4 or v7?

v7 for anything that becomes a database primary key: its time-ordered prefix keeps index inserts sequential instead of scattering them. v4 everywhere else, or where the creation time must not be inferable.

Can two UUIDs collide?

In practice, no. A v4 UUID has 122 random bits, so you would need to generate billions per second for decades before a collision became likely.

Does v7 leak when a record was created?

Yes — the first 48 bits are a millisecond timestamp, by design. That is what makes it sort well, and a reason not to use it for anything a user should not be able to date.

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