The File Extensions Database

.ASMX File Extension

  • Developer by: Microsoft
  • Category: Web Files

What is an .ASMX file?

.ASMX is ASP.NET Web Service File

Defines Web services called by an Active Server Page (.ASP file); automatically compiled by ASP.NET when a request to the service is made; can be accessed over the Internet or from a local network.

ASMX files begin with the ASP.NET directive "WebService," followed by the "Language" parameter. This is used to set the programming language to Visual Basic, C#, or JScript. They can be run using a Windows-based Web server with the .NET framework.

Programs that open ASP.NET Web Service File
Microsoft Visual Web Developer
Microsoft Visual Studio 2017

How to solve problems with ASMX files

  • Associate the ASMX file extension with the correct application. On :
    Windows: Right click on any ASMX file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.ASMX files". Mac: Right click (or Ctrl-click) the ASMX file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .ASMX is ASP.NET Web Service File. Because only the current version supports the latest ASMX file format. Search, therefore, e.g. on the Microsoft manufacturer website after an available .ASMX is ASP.NET Web Service File update.
  • To make sure that your ASMX file is not corrupted or virus-infected, get the file again and scan it with antivirus software.