How to Write CSV in .NET

Updated:July 28, 2025

Ever wondered how to quickly use C# to write to CSV? Wonder no more! IronXL provides a very quick and easy way to write data into CSV files in .NET.

How to Write CSV in .NET

Add the IronXL Library
Create a Workbook in C#
Save Excel Workbook to CSV file format

Step 1

1. Add IronXL to Your Project

Just in case you haven’t installed IronXL yet, here are the quick steps you need to take:

Open Visual Studio and select the Project menu.
Click Manage NuGet Packages.
Search for IronXL.Excel.
Click Install.

Or use the following command in the Developer Command Prompt:

Install-Package IronXL.Excel

If you would like further guidance from any of our tutorials, please follow this link: https://ironsoftware.com/csharp/excel/docs/

You can even download the file project here.

How to Tutorial

2. Create an Excel Workbook

Let’s create a quick project!

First, create an Excel workbook containing the following information:

Figure 1 - Normal Excel data to be exported to CSV

Then add the IronXL Namespace in order to be able to write to CSV files in C# using IronXL:

using IronXL;

using IronXL;

Imports IronXL

$vbLabelText $csharpLabel

3. Save Workbook to CSV

The following C# code demonstrates how to use the WorkBook object's Load method to load an Excel file. It then uses the SaveAs method to save the file as a CSV:

:path=/static-assets/excel/content-code-examples/how-to/csharp-write-to-csv-file-save.cs

using IronXL;
// Method to save an Excel workbook as a CSV file
private void button3_Click(object sender, EventArgs e)
{
    // Load the existing Excel workbook
    WorkBook wb = WorkBook.Load("Normal_Excel_File.xlsx"); // Import .xls, .csv, or .tsv file
    
    // Save the workbook as a CSV file with the worksheet name appended
    wb.SaveAs("Excel_To_CSV.csv"); // Exported as: Excel_To_CSV.Sheet1.csv
}

$vbLabelText $csharpLabel

The output CSV file appears as follows when opened in a text editor such as Notepad.

Figure 2 - Output CSV file

Library Quick Access

IronXL API Reference Documentation

Learn more and share how to merge, unmerge, and work with cells in Excel spreadsheets using the handy IronXL API Reference Documentation.

IronXL API Reference Documentation

Frequently Asked Questions

How can I write data to a CSV file using C#?

You can use IronXL to write data to a CSV file in C#. First, create an Excel workbook containing your data, then use the WorkBook object's SaveAs method to export it as a CSV file.

How do I install IronXL in a .NET project?

To install IronXL in your .NET project, open Visual Studio, go to the Project menu, select Manage NuGet Packages, search for IronXL.Excel, and click Install. Alternatively, use the command Install-Package IronXL.Excel in the Developer Command Prompt.

What is the process to convert Excel data to CSV format using C#?

The process involves adding IronXL to your project, creating an Excel workbook, and then using the SaveAs method to convert and save the workbook as a CSV file.

Where can I find documentation for IronXL?

You can find detailed documentation for IronXL on the IronXL API Reference Documentation page, which provides examples and information on how to use IronXL's functionalities.

Can IronXL handle both reading and writing of CSV files?

Yes, IronXL can read from and write to CSV files, allowing you to easily convert between Excel and CSV formats within your C# applications.

How can I troubleshoot issues with CSV file generation in C#?

Ensure that IronXL is correctly installed and referenced in your project. Check if the Excel workbook is properly loaded using the WorkBook object's Load method before saving it as a CSV.

Are there any downloadable resources to help me learn how to use IronXL for CSV conversion?

Yes, you can download example projects from the IronXL website, including a sample project demonstrating how to write to a CSV file using C# and IronXL.

What are the steps to create an Excel workbook in C#?

To create an Excel workbook in C#, use IronXL to instantiate a workbook, populate it with your data, and then manipulate it as needed for your application.

How does IronXL simplify working with Excel files in .NET?

IronXL simplifies working with Excel files by providing user-friendly methods for reading, writing, and converting Excel data, which reduces the complexity of handling Excel file operations in .NET applications.

What command is used to install IronXL via the Developer Command Prompt?

To install IronXL via the Developer Command Prompt, use the command: Install-Package IronXL.Excel.

Chaknith Bin

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Software Engineer

Chaknith works on IronXL and IronBarcode. He has deep expertise in C# and .NET, helping improve the software and support customers. His insights from user interactions contribute to better products, documentation, and overall experience.