App Store Keywords: 100 Bytes or 100 Characters?

For plain English letters, digits and commas, one character is one byte, so the two readings agree. They split once you use accented or non-Latin text, because those characters take more than one byte. Apple does not document the encoding, so count UTF-8 bytes, which is the usual assumption.

The Japanese list has fewer characters than the English one but uses more bytes, because each Japanese character takes three. A 100-byte field therefore holds about 33 Japanese characters if you used no commas, against 100 English ones. That is why a Japanese keyword list holds about a third as many characters as an English one.

Apple says to separate terms with commas and no spaces. Spaces may separate words inside one keyword phrase, for example "Real Estate". Keywords are required and can be localized, so every language needs its own 100 bytes. See the spaces after commas answer and the minimum keyword length for the other rules.

Paste your list into the keyword field packer to see the byte count per language, or follow the full workflow in the keyword field guide. Other fields use different units: the promotional text limit is 170 characters.

See also: subtitle length and app name limit.