License key generator

How to use it

1. Set how many keys, how many groups and how long each group is.
2. Add a prefix if you want one, and keep the check character on.
3. Generate, then copy the keys or download them as CSV to import into your store.

Worked out in your browser

Nothing you type here is sent to Sellstamp or anyone else; the numbers, keys and text are made in this tab.

How the keys are made

Each character comes from your browser’s cryptographic random generator, in Crockford’s base-32 alphabet: digits and capital letters without I, L, O and U, so a key read aloud or copied by hand cannot be confused. Each character carries 5 bits, so a key of five groups of five holds about 120 bits of randomness; nobody will guess one.

The check character

With it on, the last character is calculated from all the others. If a customer mistypes any single character, the key no longer matches its check character, so your software can say “typo” before asking your server. It does not make a key harder to forge: only your server’s list of issued keys does that.