I18n made easy, for Flutter!

Why you should use flutter_i18n?

The main goal of flutter_i18n is to simplify the i18n process in Flutter. I would like to recreate the same experience that you have with the Angular i18n: simple json files, one for each language that you want to support.


To use this library, you must create in your project's root the following subfolders:


and put inside them the json related to the translation, using the following configuration:

  • If you want to specify the country code


  • otherwise


Of course, you must declare the subtree in your pubspec.yaml as assets:

    - assets/flutter_i18n/

The next step consist in the configuration of the localizationsDelegates; to use flutter_i18n, you should configure as follows:

localizationsDelegates: [
        FlutterI18nDelegate(useCountryCode, [fallbackFile]),

The useCountryCode parameter depends on the json configuration:

  • if you used the pattern {languageCode}_{countryCode}, useCountryCode must be true
  • if you used the pattern {languageCode}, useCountryCode must be false

The fallbackFile parameter was entroduces with the version 0.1.0 and provide a default language, used when the translation for the current running system is not provided. This should contain the name of a valid json file in assets folder.

If there isn't any translation available for the required key, the same key is returned.

flutter_i18n in action

After the configuration steps, the only thing to do is invoke the following method:

FlutterI18n.translate(buildContext, "your.key")


  • buildContext is the BuildContext instance of the widget
  • your.key is the key to translate

From version 0.2.0 flutter_i18n manage strings that contain parameters; an example can be: "Hello, ***{user}***!" For a correct translation, you must use the third parameter of the translate method, a Map<String, String> where:

  • the keys are the placeholders used in the .json file (i.e. user)
  • the values are what you want to display