.CS·File Extension

What is a .cs file?

A .cs file is a C# Source File — C# programming language source file.

In the mime-db registry it has no registered standard MIME type. When serving this file over HTTP, use a Content-Type that matches its actual format.

When served over HTTP, responses should set the following header:

# No standard MIME type is registered for .cs

Common software that reads/writes .cs:

• Configuration files
• Data interchange between systems
• API request and response payloads
• Logs and data exports

• Open the file with Visual Studio, make your changes and save.
• Most editors preserve the original formatting and encoding — avoid changing the charset.

• Create a new file and save it with the .cs extension, or export this format from Visual Studio.

• mime-db
• refnet data sources

Updated 2026-08-18