C# File Extension
Microsoft Visual C# data
- File Type c#
- Popularity
- Application Notepad++
- Category Developer Files
What is a C# file?
Microsoft Visual C# data, identified by the C# extension, is a Developer Files type and includes 1166 files.
C# file support extends to various operating systems, including Windows, Mac OS and Linux. When working with C# files, you can rely on 6 programs, including Microsoft Visual Studio, Atom and Notepad++.
Programs that support C# files
How to open a C# file?
If you can’t open a C# file, it is usually because the necessary software is missing. To resolve the issue, select the right program from the list for your operating system. Then go to the official website of the developer, download the software, and install it.
When it comes to opening and working with C# files, Microsoft Visual Studio, Atom and Notepad++ are the top choices for users. To install the updated version of Notepad++, simply go to the Notepad++ Team site and download the installer compatible with all major platforms.
Once the process is complete, Notepad++ should take over as the default application for C# files.
Set Notepad++ as the default C# program
Changing Default Programs in Windows
- Right-click on your C# file, then choose the "Open with" option and select "Choose another application" from the available options;
- 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 C# files.
Change Default Program on Mac
- Right click or Control + left click on the desired C# file;
- Select "Open in application" and click "Other";
- At the bottom of the window, you will find the "Enable" menu. Default, will be set to "Recommended Programs";
- Choose "All Programs" in this menu and search for Notepad++. Check the box next to "Always open in app" to make it the default program.
How to edit a C# file?
To edit C# files, it is essential to install software that supports not only viewing but also editing the developer files. Online C# editors provide limited functionality compared to full-featured software for Microsoft Visual C# data.
List of Top C# editors 2026
Based on the criteria above, here is a selection of C# editors you can use.
| C# Editor Software | Developer | Platforms | Overall Rating |
|---|---|---|---|
| Windows Notepad | Microsoft | Windows | 4.8 out of 5 (35 reviews) |
| Gedit | GNOME | Linux | 4.6 out of 5 (38 reviews) |
| Notepad++ | Notepad++ Team | Windows | 4.6 out of 5 (37 reviews) |
| Sublime Text | Sublime HQ Pty | Windows, Mac OS, Linux | 4.6 out of 5 (39 reviews) |
| Microsoft Visual Studio | Microsoft | Windows, Mac OS, Linux | 4.2 out of 5 (35 reviews) |
| Atom | - | Windows, Mac OS, Linux | 4.1 out of 5 (36 reviews) |
Solve problems with C# files
Rest assured, any issues with C# files can typically be addressed with simple software adjustments. See the tips below for help.
Why does Notepad++ stop responding or crash intermittently?
Notepad++ crashes can be caused by outdated software. Keep your Notepad++ Team products up to date by installing the latest updates.
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.
What are the best practices for repairing a C# file that has gone bad?
Use a data recovery program to open the damaged C# file and from the menu choose "Repair" function to start the repair process. Allow the recovery process to complete, which will automatically repair the damaged developer files.
What are the warning signs that my C# file may be corrupted?
Common indications of damaged C# developer files are:
- Error messages appear during the course of working with the file;
- Editing the archive in Microsoft Visual Studio results in slow or unresponsive behavior;
- Opening the file results in an error or a failed attempt;
- Unexpected expansion of the total size of the C# file;
- Opening the file in Notepad++ or other programs causes them to hang or crash;