xamarin.android - Xamarin - apk App Size

Question

So, after all the hard-work developing the app using Xamarin.Forms, when I tried to create a release build today, I was shocked to see the app size is ~25MB - ~31MB (after SDK Only Linking, ProGuard, Creating apk for each abi). My resource folder is only in KBs. The apk actually was just 5MB in debug mode and was so happy to see it. I later realized that this is because of the option "Use Shared Runtime" which we are not supposed to use in Release Mode.

I then tried creating a blank Xamarin.Android app, but the release build with Linking SDK & User Assemblies, ProGuard, APK for each abi is still ~8MB to ~13MB.

Per the below link the minimum size is 2.9MB with the Hello World app, however I am unable to create such size. https://developer.xamarin.com/guides/android/advanced_topics/application_package_sizes/

For my app and the blank app I created, the necessary dlls seem to be high (example mscorlib.dll is 2.2mb etc, where as the link says after linking it will become 1 mb) Here is what I see as my assembly folder after extracting the apk

In one of the recent Microsoft tech conferences I happened to know that "9 News" app (link below) was built using xamarin, and the creators were present on the stage. However I was surprised with it's app size. It is only 5.85 MB. I am unsure how that is achieved?

Can any one help me with these?

https://play.google.com/store/apps/details?id=nineNewsAlerts.nine.com

I am also curious to know if Microsoft doing something to improve app package sizes? Or will this be resolved if they bring .NET core to xamarin?

Answer 1

Xamarin Android APK files have a larger size than usual because they include the Xamarin libraries, that translate C# code to Java code, to run in Android OS.

Using the following options, you can reduce the APK size:

• Configuration: Active (Release).
• Platform: Active (Any CPU). These are necessary to build your APK for the Google Play Store.
• Use Shared Runtime: false. If you set it to true, the APK will use Mono Runtime to execute. The Mono Runtime is installed automatically when debugging through USB, but not in the Release APK. If Mono Runtime is not installed in the device and this option is set to true in the Release APK, the app will crash.
• Generate one package (.apk) per selected ABI: false. Create your APK for as many platforms as possible, for compatibility reasons.
• Enable Multi-Dex: true, but you can set it to false if your app is not very complex (that is, has less than 65536 variables or methods, see here).
• Enable developer instrumentation (debugging and profiling): false for Release APK.
• Linking: SDK and User Assemblies. This will make the Xamarin compiler to remove all unused classes from SDK and your code, reducing the APK size.
• Supported architectures: Select all, for compatibility reasons.

Here is a print screen example: