: Font for Access Key Code I'm working on a project that will mail out access codes. Yes, using physical snail mail. The recipient needs to be able read the code and accurately type it into

@Samaraweera207

OCR-B was designed for a similar purpose. All characters are easy to distinguish both by the human eye and for optical character recognition.



OCR-B replaced a previous font called OCR-A which exaggerated even more the differences between similar letters, at the expense of making it less pleasant for humans to read. You might have seen these on bank documents, cheques, pay slips etc:



Think about base-32 encoding

But you should also think of it in another way - why not encode your access code using Base 32 (crockford version) encoding? This is an encoding which excludes the letters I, L, and O to avoid confusion with numbers, and also excludes the letter U to prevent accidental obscenity in English. Then you can use just about any font.

Vote Up Vote Down

@Kevin459

Can't go wrong with Andale Mono.

Andale Mono



Changed my answer from Courier to Andale Mono

Vote Up Vote Down

@Michele215

Search for programming fonts.

Character differentiation can be crucial when programming; these are fonts that are designed specifically with this sort of thing in mind.

Consolas is a very popular choice. Here's what those characters look like:



Here's a huge thread on programming fonts over at Stack Overflow: Recommended Fonts for Programming?



I don't want to change your criteria, but have you considered only distributing key codes that omit ambiguous characters? This is not an uncommon practice. For example, in the US all vehicles are required to have a VIN. As a measure of error prevention, they follow this rule:


does not include the letters I (i), O (o), or Q (q) (to avoid confusion with numerals 1 and 0)[1]


When the user inputs they key code, you could check for any of the invalid characters and have some sort of pop-up with a message like "Oops! You entered an I. Are you sure that's not a 1?"

Vote Up Vote Down

@Holmes874

A simple test is to go to MyFonts.com and type in a string for the sample text of all the similar characters and start looking.

For zeros, look for a font with a slashed-zero. The I/l/1 issue is a bit trickier, though.

Vote Up Vote Down