Android Compile SDK vs Target SDK: Understanding the Difference

When working with Android development, you’ll often encounter two important configuration values in your build.gradle file: compileSdkVersion and targetSdkVersion. While developers typically update both values together when new Android SDK versions are released, understanding their distinct purposes is crucial for proper app development and compatibility.

What is compileSdkVersion?

Think of compileSdkVersion as the “toolbox” that Gradle uses to build your application. It determines which version of the Android SDK will be used during the compilation process.

How it works:

Let’s say you want to use Android 12’s new Splash Screen API (SDK version 31). This API provides built-in splash screen functionality that you can customize using specific attributes. To use this feature, you need to:

1. Download SDK version 31 in Android Studio
2. Update compileSdkVersion to 31 in your gradle file

gradle

android {
    compileSdkVersion 31
    // other configurations...
}

What about older devices?

Here’s where it gets interesting. Just because you’re compiling with SDK 31 doesn’t mean you’re abandoning users on older Android versions. If your minSdkVersion is set lower than 31, you’ll need to provide fallback implementations for devices that don’t have access to the new API.

When you update compileSdkVersion, you might encounter warnings and errors during compilation. This happens because:

• Some methods or properties may be deprecated in the new SDK version
• Some features might be removed entirely
• New APIs require proper backward compatibility handling

Important: Changing compileSdkVersion alone doesn’t actually change your app’s behavior – it just gives you access to new APIs and tools during development.

What is targetSdkVersion?

If compileSdkVersion is your toolbox, then targetSdkVersion is your “promise” to the Android system. It tells the system which Android version your app was designed and tested for.

How it works:

When users run your app on a device with an Android version higher than your targetSdkVersion, the system may apply backward compatibility behaviors to ensure your app continues working as you originally designed it.

Real-world example:

Android 12 changed how custom notifications look. Previously, you could use the entire notification area freely, but Android 12 now applies a standard template to all custom notifications for consistency.

If your targetSdkVersion is set below 31:

• The system assumes you haven’t tested the new notification behavior
• It displays notifications using the old format to prevent display issues
• Your app continues working as expected

Only after you update targetSdkVersion to 31 will the new notification interface be applied to your app.

The relationship between compileSdkVersion and targetSdkVersion

While these two values serve different purposes, they’re closely related:

Key rule:

targetSdkVersion cannot be higher than compileSdkVersion

This makes logical sense – you can’t target features you don’t have access to during compilation.

Best practice:

Ideally, both compileSdkVersion and targetSdkVersion should be equal and point to the latest SDK version. However, this should only be done after thorough testing to ensure all changes introduced in that version work smoothly with your app.

Practical implications for NativeScript developers

For NativeScript developers, understanding these concepts is important because:

1. Plugin compatibility: Native plugins need to be compatible with your target SDK version
2. Platform-specific features: When accessing native Android APIs through NativeScript, you need to consider SDK version compatibility
3. App store requirements: Google Play Store has requirements for target SDK versions that affect app updates and new submissions

Summary

• compileSdkVersion: The Android SDK version used to compile your app (your development toolbox)
• targetSdkVersion: The Android version your app was designed for (your compatibility promise)

Both values are essential for handling Android compatibility, but they serve different roles in ensuring your app works correctly across different Android versions. Always test thoroughly when updating these values, and remember that while you can compile with the latest SDK, you should only target it after ensuring your app works properly with any new behaviors it introduces.