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Mobile Test Automation of Flutter Apps: Best Practices using Katalon Studio

Mobile Test Automation of Flutter Apps with Katalon Studio


Flutter, Google's open-source UI toolkit, has gained immense popularity for building natively compiled applications for mobile, web, desktop, and embedded devices from a single codebase. With its versatility, developers have embraced Flutter for creating dynamic and responsive user interfaces. However, when it comes to test automation, Flutter apps require a unique approach due to their underlying architecture. In this article, we will explore how to effectively automate testing for Flutter apps and leverage the power of Appium and Katalon Studio for seamless automation.

Benefits and Challenges of Flutter Test Automation

Test automation for Flutter apps shares similarities with automating any other mobile app development toolkit. It offers a set of advantages as well as potential challenges:


  1. Cross-Platform Testing: Flutter's cross-platform nature enables consistent testing across various platforms, reducing the need for separate testing for Android and iOS (especially using Katalon Studio’s recommended best practices).
  2. Single Codebase: Since Flutter allows a single codebase for multiple platforms, test scripts can be reused, minimizing redundancy.
  3. Quick Development: Flutter's "hot reload" feature accelerates development and debugging, enabling developers to make changes to platform-independent locators very efficiently.


  1. Preprocessing Requirement: To enable automated testing of Flutter apps, a preprocessing step is necessary. Without preprocessing, the automation will be limited, depending on the UI objects used in the app.
  2. Differences in UI Objects: Flutter apps may not behave identically to traditional apps developed in Swift or Kotlin. The effectiveness of test automation depends on the app's UI structure.

Preprocessing a Flutter App for Testing

Preprocessing is a crucial step in preparing a Flutter app for testing. It ensures that the app interacts seamlessly with test automation tools like Appium. To learn more about how to preprocess a Flutter app for testing, you can refer to the preprocess section of instructions provided by our partners at BrowserStack.

Setting Up Test Automation with Katalon Studio

To effectively use Katalon Studio for test automation of Flutter apps, follow these steps:

  1. Install Katalon Studio: Make sure you have Katalon Studio installed on your machine. You can download the latest version from the Katalon website.
  2. Install Required Mobile Automation Libraries & Drivers: Download and install the required libraries such as Appium (2.X) for mobile automation, and the necessary drivers for iOS (XCUITest) and Android (UIAutomator2). You'll need Xcode for iOS testing and Android Studio for Android testing. Make sure these tools are properly installed and configured.
  3. Appium Flutter Driver Setup: Refer to Katalon's documentation for instructions on setting up Appium Flutter Driver, desired capabilities, and custom keywords.
  4. Library Management: Download the appium_flutterfinder_java library from the Maven repository. Add the downloaded .jar file to Katalon Studio by navigating to Project > Settings > Library Management.
  5. Optional: Custom Keywords Package: Create a new keyword package and copy and paste the definition of FlutterFinder. This package will enhance user-friendly interactions for creating test scripts that require any flutter-specific locator to be used by Appium Flutter Driver if implemented within the application under test (by your developers).

Package Contents Example | Katalon Studio


Alternatively, you can also import this sub-folder (katalon.klc) into your Keywords folder:

Overcoming Limitations

In general, there is no inherent limitation in testing Flutter apps with Katalon Studio. Any perceived limitations often result from Appium's own constraints, which are typically addressed very quickly by the contributors to that initiative. Fortunately, major limitations are rarely highlighted in technical discussions, and showstoppers are seldom encountered.


Automating test scripts for Flutter apps is a process that, when done right, offers numerous benefits. Leveraging Katalon Studio and the power of Appium can make the journey more efficient. With the preprocessing step, you can ensure that your Flutter app is well-prepared for comprehensive testing. In essence, Flutter provides a versatile and dynamic platform for building applications, and Katalon can complement it seamlessly to deliver high-quality, reliable software.


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