Quick UUID Generator: GUID

Sometimes you just need one identifier, right now, on the phone in your hand. Not a code snippet, not a terminal, not a website you have to trust with it. Open the app and the identifier is already there. Tap it and it is on your clipboard.

WHICH VERSION YOU GET, AND WHEN IT MATTERS

Quick UUID generates four kinds, and the difference is worth knowing before you paste one into a database.

• v4 is pure randomness. The default, and the right choice when you need something unique and have no reason to care about order.

• v7 carries the time it was made in its leading bits, so v7 identifiers sort in the order they were created. That is what makes it pleasant as a database primary key: new rows land next to each other instead of scattering across the index.

• v1 also encodes a timestamp, alongside a random node value: nothing about the device is embedded in it. Older systems expect this one.

• v5 is the odd one out, because it is not random at all. You give it a name and a namespace, and the same name always produces the same identifier. Generate it today or next year, on this phone or another one, and the value is identical. The namespace is chosen with the built-in DNS, URL, OID and X.500 selector.

UPPERCASE OR LOWERCASE

One tap switches the output between cases. Some systems insist on uppercase, others on lowercase, and retyping a 36-character string by hand is how mistakes happen.

EVERYTHING YOU GENERATED IS STILL THERE

The full history stays on the device, with the version and the time next to every value. Tap any entry to copy it again. Useful when you generated three identifiers in a row and now need the second one back.

WORKS WITH NO NETWORK

Everything happens on the phone. No account, no sign-in, no registration: the identifiers are created on the device and never leave it, so the app keeps working on a plane, inside a locked-down office network, or in airplane mode.

WHAT IT DOES NOT DO

It generates identifiers. It does not validate or decode ones you received from somewhere else, and it does not export batches to a file.