Language and region are two settings, and they break different things. Language changes your strings. Region changes formats such as dates, numbers and currency. Test both, separately and together.
How to switch quickly
- System language. In Settings, open System, then Languages, and move a language to the top. The path varies by manufacturer and Android version.
- Region. Some devices and Android versions let you set region (and sometimes number system, first day of week, temperature unit) separately. Look under the same language settings; if you cannot find it, change the region of your language instead (for example English (United States) vs English (United Kingdom)).
- Per-app language. Android 13 and later can set a language for one app (Settings > System > Languages & input > App languages, or in the app's own settings page). If your app supports it, test that path too.
- Emulator. Create several emulators or change the language in the emulator's settings. It is the fastest way to flip languages many times.
- After switching, force-stop and reopen the app, and also change the language while the app is open to test live changes.
What to check
- Missing translations. Look for raw keys, English fallback in a non-English UI, or mixed languages on one screen.
- Long text. German and other languages often run longer than English. Look for cut-off buttons and overlapping labels.
- Plurals. "1 item" and "2 items" are not the only forms; some languages have more. Test zero, one, two and a larger number.
- Dates and times. Check order (day/month), 12 or 24 hour clocks, first day of week, time zones.
- Numbers and currency. Decimal comma versus point, thousands separators, symbol placement. Enter a number in one format and see how the app reads it.
- Right-to-left. Switch to a right-to-left language: layouts, icons that imply direction, and back arrows should mirror. See testing localization with long words and RTL.
- Sorting and search. Names with accents or other scripts should sort and search sensibly.
- Text from the server. Error messages, emails and notifications may come in another language than the UI.
- Images with text. Screenshots or banners with baked-in text do not translate.
- Keyboard. Check input with the keyboard for that language.
A fast routine
Pick three setups: your main language, one long-text language and one right-to-left language. Run the main flows in each, with a region that changes number and date format. Add more only where you have users.
Reporting
State language, region, Android version and screen, with a screenshot. For plural issues, include the number used.
Back to the Android app testing hub. Related: camera and media testing and the location and sensor checklist.
Native speakers catch wording issues you cannot. AppReviewX offers private, structured feedback; 1 feedback = 1 credit. Start free.