Flutter i18n : une base de code, toutes les langues, toutes les plateformes
Flutter utilise des fichiers ARB (Application Resource Bundle) et le package intl pour gérer la localisation sur iOS, Android, web et ordinateur de bureau à partir d'une base de code unique. L'outil gen-l10n génère du code Dart avec sécurité de types à partir de vos modèles ARB, vous offrant une sécurité à la compilation et l'autocomplétion IDE pour chaque clé de traduction.
Get started in 4 steps
Enable generation
Add the generate flag to your pubspec.yaml to enable localization code generation.
# pubspec.yaml
dependencies:
flutter:
sdk: flutter
flutter_localizations:
sdk: flutter
intl: any
flutter:
generate: trueConfigure l10n.yaml
Create l10n.yaml in your project root to configure the localization generator.
# l10n.yaml arb-dir: lib/l10n template-arb-file: app_en.arb output-localization-file: app_localizations.dart
Create ARB template
Add your source language ARB file with translation keys and metadata.
{
"@@locale": "en",
"welcome": "Welcome to {appName}",
"@welcome": {
"placeholders": {
"appName": { "type": "String" }
}
},
"itemCount": "{count, plural, =0{No items} =1{1 item} other{{count} items}}",
"@itemCount": {
"placeholders": {
"count": { "type": "int" }
}
}
}Use in your app
Wrap your app with localization delegates and use AppLocalizations.of(context) in widgets.
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
localizationsDelegates: AppLocalizations.localizationsDelegates,
supportedLocales: AppLocalizations.supportedLocales,
home: MyHomePage(),
);
}
}
class MyHomePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
final l10n = AppLocalizations.of(context)!;
return Text(l10n.welcome('Flutter'));
}
}Fonctionnalités de localisation Flutter
La localisation de Flutter en pratique
Utilisez AppLocalizations.of(context) pour accéder aux méthodes de traduction générées dans vos widgets, avec une prise en charge complète de la pluralisation et du formatage des dates.
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
class ProductPage extends StatelessWidget {
final int itemCount;
const ProductPage({required this.itemCount});
@override
Widget build(BuildContext context) {
final l10n = AppLocalizations.of(context)!;
return Column(
children: [
Text(l10n.welcome('My Store')),
Text(l10n.itemCount(itemCount)),
// Date formatting respects locale
Text(DateFormat.yMMMd(
Localizations.localeOf(context).toString()
).format(DateTime.now())),
],
);
}
}Guides connexes
Android Localization
Comparez la localisation Flutter avec les patterns natifs Android strings.xml et les qualificatifs de ressources.
iOS Localization
Découvrez comment iOS gère la localisation avec les String Catalogs et SwiftUI pour une comparaison spécifique à la plateforme.
Comparatifs TMS
Comparez les plateformes de gestion des traductions pour trouver la solution la mieux adaptée à votre projet Flutter.
Flutter i18n — Frequently Asked Questions
What are ARB files and why does Flutter use them?
ARB (Application Resource Bundle) files are JSON-based localization files used by Flutter's official gen_l10n tool. Each ARB file contains translation key-value pairs plus metadata (placeholders, descriptions, plural rules) in @-prefixed entries. Flutter's build system generates type-safe Dart code from ARB files, so accessing translations via AppLocalizations.of(context).myKey is fully typed and IDE-autocompleted. Better i18n stores and exports translations in ARB format natively.
How does Better i18n integrate with Flutter's localization workflow?
Better i18n connects to Flutter projects via the CLI. Run `better-i18n push` to upload your template ARB file (app_en.arb), have translators or AI complete translations in the dashboard, then run `better-i18n pull` to download all localized ARB files into your lib/l10n/ directory. The Flutter build system then regenerates the type-safe AppLocalizations class. This replaces manual file exchange with translators and keeps all languages in sync.
Does Flutter support ICU message format for plurals?
Yes. Flutter's gen_l10n tool uses ICU MessageFormat syntax for plural and select messages in ARB files. For example: '{count, plural, =0{No items} =1{1 item} other{{count} items}}'. The generated Dart code handles the correct plural form selection based on the active locale's CLDR plural rules. Better i18n's translation editor supports ICU syntax and validates plural forms for each target language.
What is the better_i18n Flutter package?
better_i18n is Better i18n's official Flutter/Dart SDK on pub.dev. It fetches translations from the Better i18n CDN at runtime, supporting over-the-air translation updates without requiring an app store release. The SDK implements a two-phase load pattern: it reads from local SharedPreferences storage first for instant display, then fetches fresh translations from the CDN in the background. Storage keys are compatible with the JavaScript SDKs.
How do I add a new language to a Flutter app?
Add the locale to your MaterialApp's supportedLocales list, create a corresponding ARB file (app_fr.arb for French) in your l10n directory, then run `flutter gen-l10n` to regenerate the AppLocalizations class. With Better i18n, you add the language in the dashboard, AI pre-translates all existing keys, your team reviews them, and you pull the ARB file with `better-i18n pull`. The entire process — from adding a language to having production-ready translations — takes hours instead of weeks.
Does Flutter i18n work on all platforms — iOS, Android, web, and desktop?
Yes. Flutter's localization system is cross-platform by design. The same ARB files and AppLocalizations class work identically on iOS, Android, web, macOS, Windows, and Linux. Platform-specific behaviors like date formats, number separators, and RTL text direction are handled by the flutter_localizations package and the intl library, which implements Unicode CLDR rules for each locale.
Découvrez d'autres guides sur les frameworks
Simplifiez la localisation Flutter dès aujourd'hui
Gérez vos traductions ARB avec des flux de travail propulsés par l'IA, la synchronisation CLI vers votre projet Flutter, et une livraison CDN en moins de 50 ms.