.APPX File Extension

When developers submit Windows applications to the Microsoft Store, they do so by packaging all the files and information needed to install the app within an APPX or .MSIX file. Then they submit the file to the Microsoft Store. Whenever you download and install an app from the Microsoft Store, you are actually downloading and installing the APPX or MSIX file (which, when opened, installs the app itself).

NOTE: Microsoft introduced the APPX file format with Windows 8, when the Microsoft Store was called the Windows Store. While the APPX format is still supported, the newer MSIX format is more common.

Developers typically create APPX files within Microsoft Visual Studio. To create an APPX file in Visual Studio, open the Create App Packages wizard by right-clicking your project and selecting Publish → Create App Packages .

When building an app for multiple processor architectures (x86, x64, ARM, etc), developers can bundle multiple variants in a single .APPXUPLOAD or .APPXBUNDLE package. Alternatively, developers may submit individual APPX or MSIX files to the Store for each architecture.

To open a .appx file, you need compatible software that supports this file format.