The Interviewer application responds to the device language setting of the mobile device. Localization affects the interface of the application, such as menus, dialogs and application error messages. The languages currently available are listed in the localization overview article.

The exact steps to change may differ slightly for different device models and operating system versions, but described generically in this Android HelpCenter article.

Note that you can still design the questionnaire itself in any language, including the texts of the questions, their options, instructions, and validation messages. Survey Solutions also allows multilingual questionnaires, which allow switching the language even during the interview.