diff --git a/auth/lib/app/view/app.dart b/auth/lib/app/view/app.dart
index 37967d75a6..b2abc6caa0 100644
--- a/auth/lib/app/view/app.dart
+++ b/auth/lib/app/view/app.dart
@@ -23,7 +23,7 @@ import 'package:tray_manager/tray_manager.dart';
 import 'package:window_manager/window_manager.dart';
 
 class App extends StatefulWidget {
-  final Locale locale;
+  final Locale? locale;
   const App({super.key, this.locale = const Locale("en")});
 
   static void setLocale(BuildContext context, Locale newLocale) {
diff --git a/auth/lib/locale.dart b/auth/lib/locale.dart
index c3b33e2988..7b0a34d02a 100644
--- a/auth/lib/locale.dart
+++ b/auth/lib/locale.dart
@@ -26,6 +26,7 @@ const List<Locale> appSupportedLocales = <Locale>[
   Locale("zh", "CN"),
 ];
 
+Locale? autoDetectedLocale;
 Locale localResolutionCallBack(locales, supportedLocales) {
   Locale? languageCodeMatch;
   final Map<String, Locale> languageCodeToLocale = {
@@ -35,12 +36,14 @@ Locale localResolutionCallBack(locales, supportedLocales) {
 
   for (Locale locale in locales) {
     if (appSupportedLocales.contains(locale)) {
+      autoDetectedLocale = locale;
       return locale;
     }
 
     if (languageCodeMatch == null &&
         languageCodeToLocale.containsKey(locale.languageCode)) {
       languageCodeMatch = languageCodeToLocale[locale.languageCode];
+      autoDetectedLocale = languageCodeMatch;
     }
   }
 
@@ -48,7 +51,9 @@ Locale localResolutionCallBack(locales, supportedLocales) {
   return languageCodeMatch ?? const Locale('en');
 }
 
-Future<Locale> getLocale() async {
+Future<Locale?> getLocale({
+  bool noFallback = false,
+}) async {
   final String? savedValue =
       (await SharedPreferences.getInstance()).getString('locale');
   // if savedLocale is not null and is supported by the app, return it
@@ -64,6 +69,12 @@ Future<Locale> getLocale() async {
       return savedLocale;
     }
   }
+  if (autoDetectedLocale != null) {
+    return autoDetectedLocale!;
+  }
+  if (noFallback) {
+    return null;
+  }
   return const Locale('en');
 }
 
diff --git a/auth/lib/main.dart b/auth/lib/main.dart
index 6d21f371d6..f812960a9a 100644
--- a/auth/lib/main.dart
+++ b/auth/lib/main.dart
@@ -102,7 +102,7 @@ Future<void> _runInForeground() async {
   return await _runWithLogs(() async {
     _logger.info("Starting app in foreground");
     await _init(false, via: 'mainMethod');
-    final Locale locale = await getLocale();
+    final Locale? locale = await getLocale(noFallback: true);
     unawaited(UpdateService.instance.showUpdateNotification());
     runApp(
       AppLock(
diff --git a/auth/lib/onboarding/view/onboarding_page.dart b/auth/lib/onboarding/view/onboarding_page.dart
index dff1fbc179..0061dacf3a 100644
--- a/auth/lib/onboarding/view/onboarding_page.dart
+++ b/auth/lib/onboarding/view/onboarding_page.dart
@@ -108,7 +108,7 @@ class _OnboardingPageState extends State<OnboardingPage> {
                                     child: Text("Lang"),
                                   ),
                                   onTap: () async {
-                                    final locale = await getLocale();
+                                    final locale = (await getLocale())!;
                                     // ignore: unawaited_futures
                                     routeToPage(
                                       context,
diff --git a/auth/lib/ui/settings/general_section_widget.dart b/auth/lib/ui/settings/general_section_widget.dart
index 2089b9f3ca..cb29d8483a 100644
--- a/auth/lib/ui/settings/general_section_widget.dart
+++ b/auth/lib/ui/settings/general_section_widget.dart
@@ -49,7 +49,7 @@ class _AdvancedSectionWidgetState extends State<AdvancedSectionWidget> {
           trailingIcon: Icons.chevron_right_outlined,
           trailingIconIsMuted: true,
           onTap: () async {
-            final locale = await getLocale();
+            final locale = (await getLocale())!;
             // ignore: unawaited_futures
             routeToPage(
               context,
diff --git a/auth/lib/ui/tools/app_lock.dart b/auth/lib/ui/tools/app_lock.dart
index 0d328218f1..1428c553c6 100644
--- a/auth/lib/ui/tools/app_lock.dart
+++ b/auth/lib/ui/tools/app_lock.dart
@@ -35,7 +35,7 @@ class AppLock extends StatefulWidget {
   final ThemeData? darkTheme;
   final ThemeData? lightTheme;
   final ThemeMode savedThemeMode;
-  final Locale locale;
+  final Locale? locale;
 
   const AppLock({
     super.key,
@@ -43,7 +43,7 @@ class AppLock extends StatefulWidget {
     required this.lockScreen,
     required this.savedThemeMode,
     this.enabled = true,
-    this.locale = const Locale('en', 'US'),
+    this.locale,
     this.backgroundLockLatency = const Duration(seconds: 0),
     this.darkTheme,
     this.lightTheme,
diff --git a/mobile/lib/app.dart b/mobile/lib/app.dart
index 1540a0d270..4f590e4399 100644
--- a/mobile/lib/app.dart
+++ b/mobile/lib/app.dart
@@ -25,7 +25,7 @@ class EnteApp extends StatefulWidget {
   final Future<void> Function(String) runBackgroundTask;
   final Future<void> Function(String) killBackgroundTask;
   final AdaptiveThemeMode? savedThemeMode;
-  final Locale locale;
+  final Locale? locale;
 
   const EnteApp(
     this.runBackgroundTask,
@@ -46,7 +46,7 @@ class EnteApp extends StatefulWidget {
 
 class _EnteAppState extends State<EnteApp> with WidgetsBindingObserver {
   final _logger = Logger("EnteAppState");
-  late Locale locale;
+  late Locale? locale;
 
   @override
   void initState() {
diff --git a/mobile/lib/l10n/l10n.dart b/mobile/lib/l10n/l10n.dart
index 0a74a7f1da..f45e26995c 100644
--- a/mobile/lib/l10n/l10n.dart
+++ b/mobile/lib/l10n/l10n.dart
@@ -24,17 +24,26 @@ const List<Locale> appSupportedLocales = <Locale>[
   Locale("zh", "CN"),
 ];
 
+Locale? autoDetectedLocale;
+
 Locale localResolutionCallBack(locales, supportedLocales) {
   for (Locale locale in locales) {
-    if (appSupportedLocales.contains(locale)) {
-      return locale;
+    for (Locale supportedLocale in appSupportedLocales) {
+      if (supportedLocale == locale) {
+        autoDetectedLocale = supportedLocale;
+        return supportedLocale;
+      } else if (supportedLocale.languageCode == locale.languageCode) {
+        autoDetectedLocale = supportedLocale;
+        return supportedLocale;
+      }
     }
   }
-  // if device language is not supported by the app, use en as default
   return const Locale('en');
 }
 
-Future<Locale> getLocale() async {
+Future<Locale?> getLocale({
+  bool noFallback = false,
+}) async {
   final String? savedValue =
       (await SharedPreferences.getInstance()).getString('locale');
   // if savedLocale is not null and is supported by the app, return it
@@ -50,6 +59,12 @@ Future<Locale> getLocale() async {
       return savedLocale;
     }
   }
+  if (autoDetectedLocale != null) {
+    return autoDetectedLocale!;
+  }
+  if (noFallback) {
+    return null;
+  }
   return const Locale('en');
 }
 
diff --git a/mobile/lib/main.dart b/mobile/lib/main.dart
index 9c9d42c6d8..f44a3d799f 100644
--- a/mobile/lib/main.dart
+++ b/mobile/lib/main.dart
@@ -95,7 +95,7 @@ Future<void> _runInForeground(AdaptiveThemeMode? savedThemeMode) async {
   return await _runWithLogs(() async {
     _logger.info("Starting app in foreground");
     await _init(false, via: 'mainMethod');
-    final Locale locale = await getLocale();
+    final Locale? locale = await getLocale(noFallback: true);
     runApp(
       AppLock(
         builder: (args) =>
diff --git a/mobile/lib/ui/home/landing_page_widget.dart b/mobile/lib/ui/home/landing_page_widget.dart
index e341746ac6..cc19854ed6 100644
--- a/mobile/lib/ui/home/landing_page_widget.dart
+++ b/mobile/lib/ui/home/landing_page_widget.dart
@@ -89,7 +89,7 @@ class _LandingPageWidgetState extends State<LandingPageWidget> {
                       child: Text("Lang"),
                     ),
                     onTap: () async {
-                      final locale = await getLocale();
+                      final locale = (await getLocale())!;
                       // ignore: unawaited_futures
                       routeToPage(
                         context,
diff --git a/mobile/lib/ui/settings/general_section_widget.dart b/mobile/lib/ui/settings/general_section_widget.dart
index ccc941b4ee..3532292551 100644
--- a/mobile/lib/ui/settings/general_section_widget.dart
+++ b/mobile/lib/ui/settings/general_section_widget.dart
@@ -70,7 +70,7 @@ class GeneralSectionWidget extends StatelessWidget {
           trailingIcon: Icons.chevron_right_outlined,
           trailingIconIsMuted: true,
           onTap: () async {
-            final locale = await getLocale();
+            final locale = (await getLocale())!;
             await routeToPage(
               context,
               LanguageSelectorPage(
diff --git a/mobile/lib/ui/tools/app_lock.dart b/mobile/lib/ui/tools/app_lock.dart
index cbc716d7f8..19a718b7a0 100644
--- a/mobile/lib/ui/tools/app_lock.dart
+++ b/mobile/lib/ui/tools/app_lock.dart
@@ -35,7 +35,7 @@ class AppLock extends StatefulWidget {
   final ThemeData? darkTheme;
   final ThemeData? lightTheme;
   final ThemeMode savedThemeMode;
-  final Locale locale;
+  final Locale? locale;
 
   const AppLock({
     Key? key,
@@ -43,7 +43,7 @@ class AppLock extends StatefulWidget {
     required this.lockScreen,
     required this.savedThemeMode,
     this.enabled = true,
-    this.locale = const Locale("en", "US"),
+    this.locale,
     this.darkTheme,
     this.lightTheme,
   }) : super(key: key);
diff --git a/mobile/lib/ui/viewer/file_details/creation_time_item_widget.dart b/mobile/lib/ui/viewer/file_details/creation_time_item_widget.dart
index d4f08a66f9..90b6ab9d58 100644
--- a/mobile/lib/ui/viewer/file_details/creation_time_item_widget.dart
+++ b/mobile/lib/ui/viewer/file_details/creation_time_item_widget.dart
@@ -47,7 +47,7 @@ class _CreationTimeItemState extends State<CreationTimeItem> {
   }
 
   void _showDateTimePicker(EnteFile file) async {
-    final Locale locale = await getLocale();
+    final Locale locale = (await getLocale())!;
     final localeType = getFromLocalString(locale);
     final dateResult = await DatePickerBdaya.showDatePicker(
       context,
diff --git a/mobile/lib/ui/viewer/gallery/hooks/add_photos_sheet.dart b/mobile/lib/ui/viewer/gallery/hooks/add_photos_sheet.dart
index 571b84424e..1dd6c5c8ab 100644
--- a/mobile/lib/ui/viewer/gallery/hooks/add_photos_sheet.dart
+++ b/mobile/lib/ui/viewer/gallery/hooks/add_photos_sheet.dart
@@ -218,7 +218,7 @@ class AddPhotosPhotoWidget extends StatelessWidget {
   // This custom method is required to enforce English as the default fallback
   // instead of Chinese.
   Future<AssetPickerTextDelegate> _getAssetPickerTextDelegate() async {
-    final Locale locale = await getLocale();
+    final Locale locale = (await getLocale())!;
     switch (locale.languageCode.toLowerCase()) {
       case "en":
         return const EnglishAssetPickerTextDelegate();