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Windows Phone versions

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]


This topic discusses compatibility issues between apps that target Windows Phone OS 8.0 and apps that target Windows Phone OS 7.1.

For more information about the new and changed features in Windows Phone OS 8.0, see:

This topic contains the following sections.


Windows Phone versions

The following table describes the Windows Phone releases and the corresponding operating system version numbers.

Windows Phone release

Operating system version

Windows Phone 8 

Windows Phone OS 8.0 

Windows Phone 7.5 

Windows Phone OS 7.1 

Windows Phone 7

Windows Phone OS 7.0 

Support for Windows Phone versions in the Windows Phone SDK

Windows Phone SDK 8.0 enables developers to target both the Windows Phone 8 and Windows Phone OS 7.1 platforms.

  • Apps that target Windows Phone 8 will not run on Windows Phone OS 7.1 phones.

  • Apps that target Windows Phone OS 7.1 will run on both Windows Phone OS 7.1 and Windows Phone 8 phones. The Windows Phone OS 8.0 runtime can run apps that target either version.

For more information about selecting the target version, see How to specify a target version for a new app project for Windows Phone 8.

The following table shows app compatibility on the different versions of Windows Phone phones.

Windows Phone app platform version

Windows Phone 8 phone

Windows Phone OS 7.1 phone

App that targets Windows Phone 8 

App that targets Windows Phone OS 7.1 

The following table describes the functionality available in the Windows Phone SDK 8.0 and the Windows Phone SDK 7.1.

Important Note:

The Windows Phone SDK 8.0 contains everything that you need to develop and publish apps for both Windows Phone 8 and Windows Phone OS 7.1. You do not have to have the Windows Phone SDK 7.1 installed in addition to the Windows Phone SDK 8.0. However, if you already have the Windows Phone SDK 7.1 installed, you do not have to uninstall it before installing the Windows Phone SDK 8.0.

Windows Phone SDK version

Target Windows Phone OS version

Create or open projects

Deploy or debug projects

Use Windows Phone OS 8.0 Features









Developing for Windows Phone 8 with the Windows Phone SDK 8.0 

Windows Phone OS 8.0 is the default target for new apps that you create with the Windows Phone SDK 8.0.

In an app that targets Windows Phone OS 8.0, you can reference projects and assemblies that target either Windows Phone 8 or Windows Phone OS 7.1. However you can only run your Windows Phone 8 app on the Windows Phone 8 emulator or a Windows Phone 8 phone; you cannot run your app on a Windows Phone OS 7.1 device.

Developing for Windows Phone OS 7.1 with the Windows Phone SDK 8.0 

The Windows Phone SDK 8.0 provide a full-featured environment for developing, testing, deploying, and maintaining apps that target Windows Phone OS 7.1.

Windows Phone OS 8.0 contains a large number of new APIs, features, and performance enhancements. While a lot of work has been done to ensure compatibility, developers should test their apps to ensure proper functionality on both Windows Phone 8 and Windows Phone OS 7.1. For more information on quirks and behavior changes between platform versions, see App platform compatibility for Windows Phone 8.

What you can and can’t do

Benefits of using the Windows Phone SDK 8.0 to develop Windows Phone OS 7.1 apps

When you use the Windows Phone SDK 8.0 to develop and maintain Windows Phone OS 7.1 apps, you benefit from new features in Windows Phone SDK 8.0. For example:

  • You can use the new Application Monitoring features, which include the monitoring of network usage and battery consumption. For more information, see App monitoring for Windows Phone 8. However, you cannot use the new Simulation Dashboard for apps that target Windows Phone OS 7.1.

  • You can use the improved app manifest designer to edit the manifest, instead of editing raw XML. For more information, see How to modify the app manifest file for Windows Phone 8.

Developing for Windows Phone OS 7.0 with the Windows Phone SDK 8.0 

You cannot create, develop, or run apps that target Windows Phone OS 7.0 in the Windows Phone SDK 8.0.

When you open an app that targets Windows Phone OS 7.0 in the Windows Phone SDK 8.0, the app is automatically upgraded to target Windows Phone OS 7.1.