Convert APK to XAP

A legacy Windows Phone application may require a .xap package, while the available application is an Android .apk. Because the packages target different runtimes, a usable result requires porting or rebuilding the app, not changing its filename or archive extension.

What the APK format is

An APK is the installable package format for Android phones, tablets, emulators, and other Android-based devices. It is a signed ZIP-based archive that normally contains compiled classes.dex code, resources, assets, the Android manifest, native libraries, and signing metadata.

Android Studio and Gradle produce APKs, as do Android targets in Unity, Flutter, Xamarin, React Native, and other development systems. APKs are commonly encountered when installing apps outside Google Play, testing builds, extracting resources, or archiving releases.

What the XAP format is

For this conversion, XAP means the deployment package used by Windows Phone Silverlight applications, especially Windows Phone 7 and 8. A XAP is also a ZIP-based archive, but it normally contains a compiled .NET application assembly, referenced assemblies, resources, and platform metadata such as WMAppManifest.xml and AppManifest.xaml.

Visual Studio and the matching Windows Phone SDK generate XAP files when building Windows Phone Silverlight projects. The package provides a compact, structured deployment unit for that specific runtime; its archive format does not make Android code executable on Windows Phone. Later Windows Phone application models commonly used .appx rather than .xap, so the required target platform must be identified before porting.

The .xap extension can also refer to a Microsoft XACT audio project. That is a different format from a Windows Phone package, and an APK cannot be converted into it either.

How to create a usable XAP

No reliable one-click converter exists. An APK contains Android bytecode and calls to the Android framework, whereas a Windows Phone XAP contains .NET assemblies and Silverlight metadata. The practical process is a source-level port or a new implementation.

1. Obtain the Android source. Open the project in Android Studio and inventory its screens, assets, storage, network services, permissions, background work, device APIs, and third-party dependencies. Source code is substantially easier to port than a compiled APK.
2. Inspect the APK if source is unavailable. Use apktool d app.apk -o decoded-app to extract resources and decode the manifest, or use JADX to produce approximate Java source from DEX bytecode. Decompiled code may be incomplete or obfuscated, and extracted assets and code may be subject to copyright, licensing, or anti-circumvention restrictions.
3. Install the correct legacy toolchain. Use a compatible version of Visual Studio and the Windows Phone SDK for the intended Windows Phone Silverlight target. Create a Windows Phone Silverlight project and configure its supported screen orientations, capabilities, deployment settings, and target OS version.
4. Rebuild the user interface and application logic. Recreate Android layouts in XAML, rewrite Java or Kotlin code in C# or Visual Basic, and replace Android activities, fragments, services, intents, and lifecycle handling with Windows Phone APIs. Substitute platform-specific storage, notifications, sensors, maps, authentication, billing, and networking components.
5. Replace platform metadata and assets. Import only assets that may legally be reused, add them to the Windows Phone project, create the required application manifest, and translate Android permissions into the Windows Phone capability declarations.
6. Build and test the package. In Visual Studio, select Build → Build Solution. The Windows Phone project produces the deployment package, including the generated .xap when that project type uses XAP output. Test it with the corresponding Windows Phone emulator or on an appropriately unlocked, compatible device.

Android Studio, JADX, and Apktool are inspection and extraction tools; they do not create a Windows Phone application. Visual Studio and the matching Windows Phone SDK create the XAP. Reputable online converters generally do not provide this conversion because automated archive processing cannot translate compiled code, framework APIs, interface behavior, permissions, and signing requirements. Do not upload proprietary APKs to an untrusted website.

Compatibility limitations

Renaming app.apk to app.xap, changing the ZIP extension, or placing APK contents inside a XAP archive produces no installable application. The Android manifest, Dalvik or ART bytecode, native libraries, and Android resources remain incompatible with the Windows Phone Silverlight runtime.

Dependencies on Google Play Services, Android NDK libraries, DRM, device-specific hardware, modern Android APIs, proprietary SDKs, or server-side licensing can require complete replacement or make the app impractical to port. A valid XAP also needs the signing and deployment process required by its target Windows Phone version. If the goal is only preservation or inspection, keep the original .apk and use 7-Zip, Apktool, or an APK analysis utility instead of converting it.