Inu 🐕


Inu is a simple localization tool for Flutter applications. It’s based on a class generation from structured YAML files containing all Strings for the application.

A locale class is generated from every locale file. Once generated, you can access the Strings from a Inu class instance.

Getting started

All localization files should have the same YAML-Map structure. The value of each key should contain the translated String for each language.

  • place all your localization files in a directory assets/translations/
  • add Inu to your dependencies in your Flutter app with flutter pub add inu
  • run dart run inu:init to generate the locale classes for the first time


Inu creates an abstract class called Inu, which every other locale class implements. This class is generated from the main language used during development (most likely English).

If you dont provide any translations, the Strings from the Inu class are used as a “fallback locale”.

If you have added more Strings to your locale files you can run

dart run inu:gen_classes


just inu

if you use just.

Inu checks the locale files for completeness during the generation process. Once it discovers Strings that aren’t translated, you can translate them right away in the terminal prompt or skip the process.

Once the classes have been generated, you can move on by using an instance of Inu as a Container for all your Strings.

You can write a method like this and store the returned value as a global variable or within a state management system like get_it:

Inu chooseLocale() {
  final String langCode =
      Locale(Platform.localeName).languageCode.replaceAll('_', '-');

  switch (langCode) {
    case 'de-DE':
      return DeDE();
      return EnUS();

You can also use arguments in form of a List<String> or named arguments with a Map<String, String> with the String and Text() extention tr(). Simply add curly braces to your String value in your locale files like this:

arguments: this String contains {} and {}
namedArguments: Hello, my name is {firstname} {surname}

Then use the tr() extention like this:

Text(inu.arguments).tr(['letters', 'numbers']);
String greeting = { 
    'firstname' : 'Ryan',
    'surname' : 'Stecken'});

Checkout the Example for a translated version of the Flutter demo app!

Structure of locale files

You should structure your files in form of a simple map (no lists or plain text). The map structure has to be the same for all files.


English locale file

title: app
    key1 : Value
    key2: "great value"
  anotherKey : another value

  supriseKey: ""Boo!""
  arguments: this String contains {} and {}
  namedArguments: Hello, my name is {firstname} {surname}

end: this is the end

German locale file

title: App
    key1 : Wert
    key2: "toller Wert"
  anotherKey : weiterer Wert

  supriseKey: ""Buuh!""
  arguments: dieser String beinhaltet {} und {}
  namedArguments: Hallo, mein Name ist {firstname} {surname}

end: das ist das Ende


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