In today’s globalized world, it’s crucial to create mobile applications that cater to a diverse audience. One way to achieve this is through localization, which allows your app to adapt to different languages, regions, and cultures. Flutter, the popular open-source UI toolkit, makes it easy to build natively compiled applications for mobile, web, and desktop from a single codebase. In this blog post, I’ll be sharing my expertise on Flutter localization and Flutter translation(internationalization) to help you effectively internationalize your mobile apps and reach a broader user base.

Localization is more than just translating text; it involves adapting an app’s content, layout, and design to suit the specific needs and preferences of users in different regions. By localizing your app, you can ensure a better user experience, increase user engagement, and ultimately, boost your app’s success in the global market.

To simplify your localization management and streamline the entire process, I highly recommend trying Transiyzi. This powerful tool can save you time and effort, allowing you to focus on creating amazing apps while ensuring your content is perfectly tailored for your target audience. In the sections to follow, you’ll learn the ins and outs of Flutter localization and see how Transiyzi can make the process even smoother. 

So, let’s dive into the fascinating world of Flutter localization and translation!

Flutter Internationalization: Understanding the Basics

Before we delve into Flutter localization, it’s essential to understand the concept of internationalization. Internationalization, often abbreviated as i18n, refers to the process of designing and preparing your app to support multiple languages and regions. It serves as a foundation for localization, making it easier to adapt your app to various cultures and languages with minimal code changes.

In the context of mobile development, internationalization plays a critical role in expanding your app’s reach and user base. It enables you to create a more inclusive user experience, catering to users from different backgrounds and with diverse language preferences. By internationalizing your app, you’ll be able to tap into new markets and enhance your app’s global appeal.

Transiyzi can be an invaluable asset for streamlining your app’s internationalization process. With its intuitive interface and powerful features, Transiyzi simplifies the management of translations and localization resources, helping you focus on what truly matters – building great apps for your users.

Ready to embrace the benefits of internationalization? Give Transiyzi a try and experience the difference in your Flutter app development journey!

Getting Started with Flutter Localization: dart:intl and dart:intl_translation Packages

To begin with Flutter localization, you’ll need to familiarize yourself with two essential packages: dart:intl and dart:intl_translation. The dart:intl package provides a set of utilities for working with internationalized messages, dates, numbers, and other locale-specific information. On the other hand, the dart:intl_translation package offers tools to extract and generate localized messages based on your app’s source code. Don't forget to check our other article about Mastering intl and intl_translation Packages for Dart

Here’s a step-by-step guide on setting up and using these packages for Flutter localization:

Add dependencies to your pubspec.yaml file:

To use dart:intl and dart:intl_translation, add them as dependencies in your pubspec.yaml file:

    sdk: flutter
  intl: ^0.17.0

    sdk: flutter
  intl_translation: ^0.17.10

Create an ARB (Application Resource Bundle) file:

ARB files are used to store localized messages in a simple JSON format. Create a folder named “l10n” in your project’s root directory, and within it, create a file named “app_en.arb” for English translations. For example:

  "helloWorld": "Hello World!"

Generate Dart localization files:

Run the following command in your terminal to generate the necessary localization files:

flutter pub run intl_translation:generate_from_arb --output-dir=lib/l10n --no-use-deferred-loading lib/localizations.dart l10n/app_*.arb

Implement the Localization Delegate:

In your app, create a new file named “localizations.dart” and implement a localization delegate class. This class will be responsible for loading the correct translations based on the user’s locale.

Update your MaterialApp widget:

To enable localization in your app, update your MaterialApp widget with the localization delegate and supported locales:

  localizationsDelegates: [
  supportedLocales: [
    const Locale('en', ''),
    // Add more supported locales here
  // ...

Use localized messages in your app:

Finally, you can use the generated localizations in your app’s widgets. For example:


Managing localization efforts can be a daunting task, but Transiyzi makes it easier by offering an efficient solution to keep your translations organized and up-to-date. By using Transiyzi, you can simplify your localization management, track changes, and collaborate with your team, all in one place.

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Flutter Localization: Best Practices

Now that you’re familiar with the basics of Flutter localization, let’s explore some best practices that can help you implement localization effectively and maintain consistency across languages and regions.

Use descriptive keys for localized messages:

Choose descriptive and meaningful keys for your localized messages to make it easier for translators to understand the context. This will help ensure accurate translations and a better user experience.

  "signInButton": "Sign In",
  "signUpButton": "Sign Up"

Separate language and region-specific resources:

Organize your resources by separating them based on language and region. This will allow you to easily manage translations and update them when needed. For instance, you can create separate ARB files for British English and American English:


Use number, date, and currency formatting:

To display numbers, dates, and currencies correctly for different locales, use the NumberFormat, DateFormat, and Currency classes provided by the dart:intl package.

final numberFormat = NumberFormat.currency(locale: 'en_US', symbol: '\$');
final formattedNumber = numberFormat.format(1234.56); // Output: $1,234.56

Plan for text expansion and UI adjustments:

Some languages may require more space to convey the same meaning as English. Plan for text expansion and make your UI flexible to accommodate different text lengths and font sizes.

Test your localized app on multiple devices:

Ensure that your localized app works correctly on various devices with different screen sizes and resolutions. This will help you identify any layout issues that may arise due to localization.

Transiyzi can help you efficiently manage your localization efforts by offering a comprehensive platform for organizing, updating, and tracking translations. With Transiyzi, you can stay on top of your localization game and ensure a consistent user experience across all supported languages and regions.

Upgrade your Flutter localization process with Transiyzi and experience the benefits first-hand!

Advanced Flutter Localization Techniques

As you become more experienced with Flutter localization, you may encounter more complex scenarios that require advanced techniques. In this section, we’ll discuss how to handle such situations and how to support right-to-left languages.

Handling plurals and gender:

To manage plurals and gender-specific translations, you can use the Plural and Gender classes provided by the dart:intl package. These classes enable you to handle variations in your translations based on numbers or gender.

For example, to handle plurals in your ARB file:

  "inboxMessages": "{count, plural, =0 {No messages} =1 {1 message} other {{count} messages}}"

And in your Dart code:

Text(AppLocalizations.of(context).inboxMessages(5)) // Output: 5 messages

Supporting right-to-left languages:

Some languages, such as Arabic and Hebrew, are written and read from right to left. To provide proper support for right-to-left languages in your app, you can use the Directionality widget and the TextDirection property.

In your MaterialApp widget, set the textDirection property based on the user’s locale:

  builder: (context, child) {
    return Directionality(
      textDirection: _getTextDirection(context),
      child: child,
  // ...

Localization of images and assets:

In some cases, you may need to localize your images and assets to cater to different regions or cultures. You can organize your assets in separate folders based on the locale and load them dynamically using the AssetImage class.

For example, organize your assets like this:


And load the localized asset in your Dart code:


Leveraging Transiyzi for advanced localization support can save you time and effort, making it easier to manage complex localization scenarios. With its user-friendly interface and powerful features, Transiyzi enables you to maintain a high-quality user experience, regardless of the language or region your app supports.

Take your Flutter localization to the next level with Transiyzi and see the difference it can make in your app development journey!

Testing Your Flutter Localization

Testing your localized app is crucial to ensure that it provides a consistent and high-quality user experience across all supported languages and regions. In this section, we’ll discuss the importance of testing localized apps and share some tips for effective localization testing.

Importance of testing localized apps:

Testing localized apps helps you identify and fix issues related to translations, layout, and functionality. It also ensures that your app adapts seamlessly to different languages, devices, and user preferences, providing a flawless experience for all users.

Tips for effective localization testing:

  • Test on various devices: Make sure to test your localized app on different devices with varying screen sizes, resolutions, and operating systems. This will help you identify and resolve any potential layout or compatibility issues.
  • Use pseudo-localization: Pseudo-localization is a technique that replaces the original text with an altered version, simulating the text expansion that occurs in certain languages. This can help you detect layout issues early in the development process.
  • Test in multiple languages: Test your app in all supported languages, and pay special attention to languages with unique characteristics, such as right-to-left languages or languages with special characters.
  • Test with real users: Conduct user testing with native speakers of the supported languages. Their feedback can help you identify any issues related to translations, cultural appropriateness, or user experience.
  • Automate localization testing: Use automated testing tools and frameworks to streamline your localization testing process and ensure consistent results.
    Transiyzi can help simplify your localization testing process by providing a centralized platform to manage and update your translations. With Transiyzi, you can easily track changes, collaborate with your team, and maintain a high-quality user experience across all languages and regions.

Trust Transiyzi to make your Flutter localization testing more efficient and effective. Try it today and experience the benefits for yourself!


Flutter localization is an essential aspect of mobile app development that enables you to reach a global audience and provide a tailored user experience to users from diverse backgrounds. By understanding the basics of Flutter internationalization, leveraging the dart:intl and dart:intl_translation packages, and following best practices, you can ensure that your app is ready to cater to users from various languages and regions.

Throughout this blog post, I’ve highlighted the importance of using a reliable and efficient localization management tool like Transiyzi. By streamlining your localization efforts, Transiyzi can help you save time, reduce complexity, and maintain a consistent user experience across all supported languages and regions.

As a developer, you’ll appreciate the benefits of having an intuitive, powerful, and user-friendly tool like Transiyzi by your side. It can make the entire localization process a breeze and allow you to focus on what truly matters – building amazing apps for your users.

Don’t let the challenges of localization hold you back. Give Transiyzi a try today and unlock the full potential of your Flutter app in the global market!