I've been facing this really frustrating issue where users from the US and UK keep emailing us saying that our app has suddenly changed to Chinese. I was totally confused since we don't even have internationalization set up—it's supposed to be English only! I asked for screenshots, thinking maybe they were using a fake APK, but nope, the UI was completely in English. The strange part was the error messages, which appeared in full Chinese, like asking users to fill required fields. After digging into it for three days, I finally found out that one user had a Chinese keyboard on her Samsung phone since she's learning Mandarin. On certain Android phones like Samsung and Xiaomi, secondary keyboards can mess with the locale settings, making the system think Chinese is the primary language even though the system language is set to English. It's wild! I fixed this by checking the actual system language instead of just the default locale and also added a language picker in the settings. I feel pretty dumb about how long this took to figure out. If you're also getting odd bug reports, definitely ask users about their device settings—it's usually something like this!
1 Answer
You're so right about the Locale.getDefault() behavior—it has caused chaos for a lot of development teams! We had a similar issue where dates showed up incorrectly for users who had a Japanese keyboard active. The key takeaway is that Locale.getDefault() does not equal the user's actual language preference on Android. Instead, try using Resources.getConfiguration().getLocales().get(0) on API 24 and above, and context.resources.configuration.locale for older versions. The system language and keyboard locale can really be different, so it’s important to remember that! Also, check out AppCompatDelegate.setApplicationLocales() if you want to allow users to pick their preferred language—it saves settings across app restarts and isn’t affected by the system settings at all.
Haha, totally get what you mean! These kinds of bugs make you question everything you thought you knew about your app!