ASAX File Extension
ASP.NET Application Optional Source Format
- File Type asax
- Developer Microsoft
- Popularity
- Application Notepad++
- Category Developer Files
- Format Text
What is a ASAX file?
Files with the ASAX extension are specifically tied to ASP.NET Application Optional Source Format, a Developer Files type, and there are 1166 files in this category.
Microsoft, the developer of the ASP.NET Application Optional Source Format (ASAX), has released file format and 242 programs designed to handle them.
ASAX files are compatible with various operating systems, including Mac OS, Windows and Linux. There are 6 programs available to open a ASAX file, including popular tools like Microsoft Visual Studio, Adobe Dreamweaver and Notepad++.
Programs that support ASAX files
How to open a ASAX file?
If you are having trouble opening a ASAX file, it usually means the right software is not installed. Choose a program from the list that matches your operating system. Next, visit the official website of the developer, download the software, and install it on your device.
Microsoft Visual Studio, Adobe Dreamweaver and Notepad++ are among the most widely used programs for handling ASAX files. To set up the newest version of Notepad++ on your device, simply go to the official Notepad++ Team website. There you can download the edition compatible with every operating system.
Once setup is done, your operating system should assign Notepad++ as the default app for ASAX files.
Set Notepad++ as the default ASAX program
Change Default Program on Mac
- Right click or Control + left click on the desired ASAX file;
- Choose "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 Notepad++. Check the box next to "Always open in app" to make it the default program.
Change default programs in Windows
- To get started, right-click your ASAX file, then choose "Open With" and select "Choose Another Application" from the context menu;
- In the pop-up window, select the Notepad++ application;
- Check the "Always use this application" checkbox, and then click "OK" to apply the selected application as the default for opening ASAX files.
Solve problems with ASAX files
If you encounter issues with ASAX files, don’t worry—most can be fixed with minor software adjustments. Refer to the troubleshooting tips below.
What are the steps to repair a damaged ASAX file?
Start a data recovery program and open the damaged ASAX file. Then, choose the "Repair" option from the menu. Please wait patiently for the recovery process to finish as it will automatically repair the damaged developer files.
How can I determine if my ASAX file is damaged?
The signs of corrupted ASAX developer files can manifest as:
- Trying to work with the archive in Notepad++ or other programs causes instability or program crashes;
- Error notifications appear during file manipulation;
- The file does not open correctly or displays error messages;
- An unexplained increase in the size of the ASAX file;
- The file shows slow performance when edited in Microsoft Visual Studio;
What are the reasons behind Notepad++ crash?
Insufficient software updates are a likely cause of Notepad++ crashes. Be sure to install the latest updates for Notepad++ Team products.
Restarting your computer will solve many common problems, which is why it’s the first thing you should do before changing any settings related to the software.
How to edit a ASAX file?
To modify ASAX files, it is necessary to install dedicated software that lets you open and edit developer files. Online ASAX editors generally offer fewer tools compared to programs designed for ASP.NET Application Optional Source Format.
Best ASAX editors 2026
Following these criteria, we have put together a list of recommended ASAX editors.
| ASAX Editor Software | Developer | Platforms | Overall Rating |
|---|---|---|---|
| Microsoft Visual Studio | Microsoft | Windows, Mac OS, Linux | 4.2 out of 5 (35 reviews) |