Sveltekit demo with i18n

Routing

use lang-codes in url for locale (/de, /cs)
hide default language lang-code in url (en is just /)
detect locale from browser (if it is not set by url or cookie)
if you set the language, save the locale to cookie for next visit

To do:

/src/utils/replaceLocaleInUrl.ts line:26 & line:13 change the condition based on defined languages instead of a string
/src/utils/assignLocale.ts line:12 load default language dynamicaly