How it works
Set how many letters and digits, and this random letter and number generator fills the pattern, opening on one of each. Draw up to 1,000 with no repeats and copy them as raffle tickets, table labels or sample IDs.
Read the full guide
Count the codes in a pattern
Each letter place has 26 choices and each digit place has 10, so multiply. One letter and one digit give 26 × 10 = 260 codes. Two of each, such as KT48, give 67,600. Mixed order lets B7 come out as 7B too, which doubles 260 to 520.
What the look-alike switch leaves out
A hand-written O passes for 0, and I or a small l passes for 1. Tick Leave out look-alikes and I, L and O go, the same three that Crockford's Base32, an alphabet made to be read over a telephone, drops for that reason. All ten digits stay, so a round mark is always zero, and 260 codes become 230. Canada's postal codes, written A1A 1A1, skip D, F, I, O, Q and U.
- For a raffle, make the batch in one press and paste it twice: one column to hand out, one to cut up for the bowl.
- No repeats holds inside one press only: twenty codes like B7 drawn one at a time have a 53% chance of a match.
- To mark work without names, draw one code per student, then match names to codes in the random pairing generator.
Questions and answers
Can I generate a random code for a login or a voucher here?
No. A random code here is a label for something you can see: a ticket, a seat, a jar. It is short and stays in the Made here list. A secret needs the opposite, and a program can list all 67,600 KT48-style codes at once.
Is this an alphanumeric character generator?
Yes. Alphanumeric strings join letters and digits, here up to eight of each. In Mixed order they land in any place: K4T9, 7QM2 or 38DW. With three or more letters, read the batch before sharing it: random letters now and then spell a word.
Why use random codes and not 1, 2, 3?
Numbers in a row give things away. Ticket 214 tells the buyer that at least 214 were sold, and a cup marked A or 1 in a taste test can read as first place. K4 says nothing about order or rank.