How to manually add a splash screen

Projects created using Uno Platform 4.8 or later have the Uno.Resizetizer package installed by default. Simply provide an SVG file, and the tool handles the task of generating various image sizes. That package updates the build process to automate configuring a splash screen for each platform.

While the new templates simplify adding a splash screen, this article covers how to add one to your application manually if using Uno.Resizetizer is not warranted.


If your solution was generated using the older templates, it is possible to configure these projects to use Uno.Resizetizer instead. That process makes the steps below unnecessary.

See the guide How-To: Get Started with Uno.Resizetizer for more information.


1. Shared splash screen image resources

  • Review Assets and image display to understand the present support for various image asset types

  • Prepare your images intended for the splash screen under different resolutions, eg:

    File name Width Height
    SplashScreen.scale-100.png 216 148
    SplashScreen.scale-125.png 270 185
    SplashScreen.scale-150.png 324 222
    SplashScreen.scale-200.png 432 296
    SplashScreen.scale-300.png 648 444
    SplashScreen.scale-400.png 864 592
  • Refer to this table to see values for the different scales required.

    • You can instead provide only a single image named SplashScreen.png without the scale-000 qualifier.


      Regardless if you provide a single image or multiple images, you would always refer to this image as SplashScreen.png.

  • Add these images under the Assets\ folder of the MyApp project, right-click on each image, go to Properties, and set their build action as Content.

2. Windows

  • In the MyApp project, open the file Package.appxmanifest and navigate to Visual Assets > SplashScreen.

  • Make sure the value for Preview Images > Splash Screen is set to Assets\SplashScreen.png


3. Android

  • In the MyApp project, open the subfolder for Platforms/Android

  • Navigate further to the file at Resources/values/Styles.xml

  • Styles.xml contains Android-specific customizations for the splash screen. Inside, look for the AppTheme style and add an <item> under it:

    <item name="android:windowBackground">@drawable/splash</item>
  • Navigate upward to Resources/drawable, and create a new XML file named splash.xml:

    <?xml version="1.0" encoding="utf-8"?>
        <layer-list xmlns:android="">
            <!-- background color -->
            <color android:color="#101010"/>
            <!-- splash image -->
            <bitmap android:src="@drawable/assets_splashscreen"
                    android:gravity="center" />

    Before Uno.UI 4.5, the @drawable/assets_splashscreen source should be @drawable/splashscreen. See the breaking changes section of that release.

  • Make sure splash.xml is added as an AndroidResource in the Droid project file: [Project-name].Droid.csproj.

    • This is not always done automatically and may occur if splash.xml was created and added outside the IDE.

        <AndroidResource Include="Resources\drawable\splash.xml" />

      After modifying splash.xml, you may run into errors like these while trying to debug:

      Resources\drawable-mdpi\SplashScreen.png : error APT2126: file not found.
      Resources\drawable-hdpi\SplashScreen.png : error APT2126: file not found.

      Simply rebuild the Android target to get rid of these errors.

4. iOS/MacCatalyst

  • In the MyApp project, open the subfolder for Platforms/iOS or Platforms/MacCatalyst.

    • Delete the old splash screen files:
      • Resources\SplashScreen@2x.png
      • Resources\SplashScreen@3x.png
      • LaunchScreen.storyboard
  • Create a new StoryBoard named LaunchScreen.storyboard:

    • Right-click the project subfolder you're working with (ex: MyApp/Platforms/iOS)
    • Select Add > New Item...
    • Create a Visual C# > Apple > Empty Storyboard
  • In the Toolbox window, drag and drop a View Controller and then an ImageView inside the View Controller

    • Enable the Is initial View Controller-flag on the View Controller.


    • To have an image fill the screen, set your constraints as below


    • Set the Content Mode to Aspect Fit


    • In the Properties > Storyboard Document window, select the Can be Launch Screen checkbox.


  • Close the designer and open the .storyboard file.

    • Add your image path to the Image View

      <imageView ... image="Assets/SplashScreen">
  • Open info.plist and update the UILaunchStoryboardName value to LaunchScreen.


    iOS caches the splash screen to improve the launch time, even across re-installs. In order to see the actual changes made, you need to restart the iPhone or simulator. Alternatively, you can rename the CFBundleIdentifier in info.plist incrementally (eg: MyApp1 -> MyApp2) before each build.

5. WebAssembly

  • The default splash screen configuration for WebAssembly is to use the Uno Platform logo as a placeholder.

  • An Platforms/WebAssembly/WasmScript/AppManifest.js file contains some app settings, including properties to customize its splash screen. This file is found in the MyApp project.

General properties

You can customize the splash screen image and background color by adjusting several key properties:

Property Description Notes
accentColor Color of the progress indicator's filled-in portion displayed during application launch Default value is #F85977
displayName Default name visible in the browser window's title to represent the application N/A
splashScreenColor Background color of the screen displayed during application launch Any values assigned to the theme-aware properties are ignored unless this property is set to transparent.

If the theme-aware properties are unassigned, the default browser background color will be used instead.
splashScreenImage Path to an image that will be visible on the screen displayed during application launch You currently need to set an explicit scale for the image

splashScreenColor allows you to maintain a background color regardless of the system theme. However, a simple method to make the splash screen theme-aware is to assign transparent as its value or by omitting that property altogether.

Theme-aware properties


The section below contains optional properties. If nothing is assigned to them, the value of splashScreenColor will be used under both themes as the background color.

Uno Platform supports theme-aware backgrounds as an optional customization for splash screens. Set the following properties to adjust the splash screen based on a system theme:

Property Description Notes
lightThemeAccentColor Color of the progress indicator's filled-in portion displayed during application launch if a system light theme is enabled Default value is #F85977
darkThemeAccentColor Color of the progress indicator's filled-in portion displayed during application launch if a system dark theme is enabled Default value is #F85977
lightThemeBackgroundColor Background color of the screen displayed during application launch if a system light theme is enabled Default value is #F3F3F3
darkThemeBackgroundColor Background color of the screen displayed during application launch if a system dark theme is enabled Default value is #202020
  • Code example:

    var UnoAppManifest = {
        splashScreenImage: "Assets/SplashScreen.scale-200.png",
        splashScreenColor: "transparent",
        displayName: "SplashScreenSample"

See also