How to Test Dynamic Type in iOS Simulator for Better Accessibility

How to Test Dynamic Type in iOS Simulator for Better Accessibility

11 April 2024 Stephan Petzl Leave a comment Tech-Help

Ensuring that your iOS application supports Dynamic Type is crucial for accessibility, allowing users with various visual preferences to use your app comfortably. This guide will walk you through the process of testing Dynamic Type, specifically larger font sizes, within the iOS Simulator.

Setting Up Dynamic Type in Xcode

To begin testing Dynamic Type in the iOS Simulator, you can add a specific launch argument to your Xcode scheme. This method allows you to automate the process and is especially useful for creating screenshots with larger font sizes using tools like Fastlane Snapshot.

Steps to Configure Dynamic Type via Xcode Scheme:

  1. Open your project in Xcode.
  2. Select your active scheme from the toolbar at the top of your Xcode window.
  3. Choose ‘Edit Scheme’ from the dropdown menu.
  4. Go to the ‘Run’ section on the left panel.
  5. Under the ‘Arguments’ tab, find ‘Arguments Passed On Launch’.
  6. Add the following argument with the preferred content size category:
    -UIPreferredContentSizeCategoryName UICTContentSizeCategoryXL
  7. Close the scheme editor and run your app to apply the changes.

Replace UICTContentSizeCategoryXL with any of the following values based on the desired font size:

  • UICTContentSizeCategoryXS
  • UICTContentSizeCategoryS
  • UICTContentSizeCategoryM
  • UICTContentSizeCategoryL
  • UICTContentSizeCategoryXL
  • UICTContentSizeCategoryXXL
  • UICTContentSizeCategoryXXXL
  • UICTContentSizeCategoryAccessibilityM
  • UICTContentSizeCategoryAccessibilityL
  • UICTContentSizeCategoryAccessibilityXL
  • UICTContentSizeCategoryAccessibilityXXL
  • UICTContentSizeCategoryAccessibilityXXXL

For Fastlane Snapshot integration, add the launch argument as follows:

app.launchArguments += [ "-UIPreferredContentSizeCategoryName", "UICTContentSizeCategoryXL" ]

Alternative Method: Using Accessibility Inspector

As of Xcode 8 and above, an alternative to the launch arguments approach is to use the Accessibility Inspector tool, which provides a more visual interface for testing different accessibility features, including Dynamic Type.

Accessing Accessibility Inspector:

  1. Open Xcode.
  2. From the menu bar, navigate to Xcode > Open Developer Tool > Accessibility Inspector.
  3. Ensure that ‘Larger Text’ is enabled in your simulated device’s settings under General > Accessibility > Larger Font.
  4. With Accessibility Inspector open, you can adjust the Dynamic Type settings as needed.

In Xcode 11 and later, there’s an added feature called Environment Overrides which further simplifies testing different UI environments, including text size.

Dynamic Type at the Application Level

For a more granular approach, it is also possible to dynamically alter the Dynamic Type settings at the application level using the UITraitCollection API. This can be particularly useful for unit and UI tests where you need to simulate different user settings.

Refer to the UITraitCollection API documentation for detailed instructions on how to implement this in your testing suite.


Testing Dynamic Type is an essential step in ensuring that your iOS application is accessible to all users. By using the methods outlined above, you can easily simulate different font sizes in the iOS Simulator to check how your app’s UI adapts to these changes.

Like this article? there’s more where that came from!