Kotlin Multiplatform library for in-app language switching on Android and iOS.
No Compose dependency — exposes a StateFlow<String> you consume however you like.

Android (API 30)	Android (API 36)	iOS

Every KMP project that needs in-app language switching reinvents the same glue code. KLocale packages the correct platform calls (AppCompatDelegate on Android, NSUserDefaults on iOS) behind a single shared API.

// build.gradle.kts
dependencies {
    implementation("io.github.nowjordanhappy:klocale:1.0.0")
}

Requires Android minSdk 21+. AppCompat 1.7 handles the backport automatically; on Android 13+ it delegates to the system LocaleManager.

val klocale = KLocale(
    supported = listOf("es", "en", "pt", "fr", "it"),
    fallback = "en",
    onChanged = { code -> settings.putString("language", code) } // optional
)

// Observe in ViewModel / Composable
klocale.current               // StateFlow<String>

// Map device locale to your supported list (e.g. "fr-CA" → "fr")
klocale.getSystemDefault()

// Switch language
klocale.set("es")

onChanged is the only persistence hook — use DataStore, multiplatform-settings, or nothing. KLocale does not persist anything itself.

AppCompat 1.7.0 is pulled in automatically.

Add to <application> in AndroidManifest.xml:

<application
    android:localeConfig="@xml/locale_config"
    ...>

Create res/xml/locale_config.xml listing every code from your supported list:

<?xml version="1.0" encoding="utf-8"?>
<locale-config xmlns:android="http://schemas.android.com/apk/res/android">
    <locale android:name="es"/>
    <locale android:name="en"/>
    <locale android:name="pt"/>
    <locale android:name="fr"/>
    <locale android:name="it"/>
</locale-config>

Without this the library still works, but the per-app language option won't appear in Settings → Apps → [App] → Language on Android 13+.

set() triggers an Activity recreation on Android (same behavior as the system language switch). Save any unsaved state before calling set().

<key>CFBundleLocalizations</key>
<array>
    <string>es</string>
    <string>en</string>
    <string>pt</string>
    <string>fr</string>
    <string>it</string>
</array>

set() writes to NSUserDefaults (AppleLanguages key) and updates current immediately. The system language change takes effect on the next app launch — this is standard iOS behavior.

MIT