App Store Localization for Czech: Storefronts, Bytes, Keywords

Apple's localizations table never names Czech as a default language. It appears as an additional language in 1 more: Czechia. The default language listed next to it is English (U.K.).

Apple's keyword reference allows 100 bytes, not 100 characters. Counted as UTF-8, the example below contains 47 one-byte and 7 two-byte characters (separators excluded). Only the accented letters cost two bytes, so the field holds between 50 and 100 letters depending on how many accents you use. The words below are a hypothetical keyword list for a habit tracker called Streakly; they are illustrations, not validated search terms, and each has at least three characters.

Joined with commas and no spaces after them, the field is:

návyky,rutina,cíle,připomínky,motivace,denní plán,disciplína

That is 60 characters and 67 bytes: 61 bytes of keywords plus 6 commas, leaving 33 of the 100 bytes free. The byte counts assume UTF-8; confirm the final count in App Store Connect before you save.

For Czechia the question is simple: either your listing falls back to English or you add the cs locale. The table does not show Slovakia under Czech; Slovak has its own locale entry (sk), and it is a separate field from Czech. The Czechia keyword page covers the storefront and the Slovakia page the neighbor.

The shortcode in App Store Connect's API is cs, not the ISO country-style cz. That matters if you automate uploads; see the guide to uploading metadata with the App Store Connect API.

Czech marks vowels with an acute accent and consonants with a caron (háček), as in ř, š and č. Every one of those letters takes two bytes, as do accented vowels such as á, í and ý. A typical Czech word of six letters costs seven or eight bytes.

Apple does not document whether a search typed without diacritics matches a keyword that has them, which many Czech users do on phones. That makes the diacritic-free form a plausible second keyword to test, not a proven one. Polish has the same issue with different letters.

LocalASO checks keywords in 52 App Store storefronts, each in the storefront's local language, so you can compare your Czech candidates with the English ones in one place. Keywords, ranks and listings stay in a database on your Mac. LocalASO is a one-time $29 purchase and the app needs a license key to run; the setup is in the localization docs and the price is on the pricing page. To test the field you just built, use the keyword field checker, or browse every language page. Related languages: Polish, Croatian, English (U.K.).