ASMX File Extension
ASP.NET Web Service Format
- File Type asmx
- Developer Microsoft
- Popularity
- Application ASP.NET
- Category Web Files, Developer Files
What is a ASMX file?
ASP.NET Web Service Format works with the ASMX file extension and is classified under Web Files and Developer Files, with a total of 1449 files.
With the creation of the ASP.NET Web Service Format (ASMX), Microsoft introduced file format along with 242 programs built for their use.
ASMX files are supported by Windows, Linux and Mac OS. You can open a ASMX file using one of 12 programs, for example ASP.NET, Internet Explorer and Opera Browser.
Programs that support ASMX files
How to open a ASMX file?
The most common reason why a ASMX file cannot be opened is the absence of required software. To fix this, select a compatible program from the list. Then visit the official developer website via the provided link, download the program, and install it on your system.
The most popular programs for working with ASMX files are ASP.NET, Internet Explorer and Opera Browser. To get the latest version of ASP.NET, open the Microsoft website where a universal installer for all operating systems is available.
Once setup is done, your operating system should assign ASP.NET as the default app for ASMX files.
Make ASP.NET the default ASMX viewer
Changing the default program in Windows
- Start by right-clicking on your ASMX file and selecting the "Open With" option. From there, click "Choose another app" to continue;
- Inside the popup window, scroll through the list of applications and specifically choose ASP.NET as the application to associate with your ASMX file;
- Check the "Always use this app" checkbox and click "OK".
Change the default app to open files on Mac
- Right click or use Control + Left Click on the desired ASMX file to access a dropdown menu of actions;
- Select "Open in application" and click "Other";
- Scroll down to the bottom of the window, where you will find the "Enable" menu. Default, "Recommended Programs" will be selected;
- In this menu, choose "All Programs" and navigate to ASP.NET. Check the box next to "Always open in app" to make it the default program.
How to edit a ASMX file?
To edit ASMX files, you need to install specialized software that allows you not only to open but also to modify web files. Online ASMX editors usually provide fewer features than software created specifically for ASP.NET Web Service Format.
List of Top ASMX editors 2026
Following these criteria, we have put together a list of recommended ASMX editors.
| ASMX Editor Software | Developer | Platforms | Overall Rating |
|---|---|---|---|
| ASP.NET | Microsoft | Windows | 4.6 out of 5 (42 reviews) |
| Adobe Dreamweaver | Adobe | Windows, Mac OS | 4.5 out of 5 (38 reviews) |
| Adobe Contribute | Adobe | Windows | 4.4 out of 5 (42 reviews) |
Finding answers to ASMX file problems
If you encounter issues with ASMX files, don’t worry—most can be fixed with minor software adjustments. Refer to the troubleshooting tips below.
What are the signs that my ASMX file is damaged?
Corrupted ASMX web files may have one or more of the following symptoms:
- Poor performance when editing a file in ASP.NET;
- Opening or processing the file in ASP.NET or other programs causes instability or crashes in the program;
- The file shows errors when trying to open it or does not open completely;
- Unexpected expansion of the total size of the ASMX file;
- Working with the file triggers the display of error messages;
Why does ASP.NET quit or crash unexpectedly?
ASP.NET crashes can be attributed to outdated software. Make sure you have installed the latest updates for Microsoft products.
A computer restart is often the key to solving numerous common problems. That’s why, it is recommended to restart the computer before making any changes to the software settings.
What methods can be used to repair a damaged ASMX file?
Use a recovery program to open the damaged ASMX file and navigate to the "Repair" menu item. Wait for the recovery process to finish, as it will automatically repair damaged web files.