1. IronXL
2. Tutorials
3. Opening an Excel File in C#

C# Write to Excel [Without Using Interop] Code Example Tutorial

Chaknith Bin

Updated:June 22, 2025

Follow step-by-step examples of how to create, open, and save Excel files with C#, and apply basic operations like getting sum, average, count, and more. IronXL.Excel is a stand-alone .NET software library for reading a wide range of spreadsheet formats. It does not require Microsoft Excel to be installed, nor depends on Interop.

Overview

Use IronXL to Open and Write Excel Files

Open, write, save, and customize Excel files with the easy-to-use IronXL C# library.

Download a sample project from GitHub or use your own, and follow the tutorial.

1. Install the IronXL Excel Library from NuGet or the DLL download
2. Use the WorkBook.Load method to read any XLS, XLSX, or CSV document.
3. Get Cell values using intuitive syntax: sheet["A11"].DecimalValue

In this tutorial, we will walk you through:

• Installing IronXL.Excel: how to install IronXL.Excel to an existing project.
• Basic Operations: basic operation steps with Excel to Create or Open workbook, select sheet, select cell, and save the workbook.
• Advanced Sheet Operations: how to utilize different manipulation capabilities like adding headers or footers, mathematical operations, and other features.

Open an Excel File: Quick Code

:path=/static-assets/excel/content-code-examples/tutorials/csharp-open-write-excel-file-1.cs

using IronXL;

WorkBook workBook = WorkBook.Load("test.xlsx");
WorkSheet workSheet = workBook.DefaultWorkSheet;
IronXL.Range range = workSheet["A2:A8"];
decimal total = 0;

// iterate over range of cells
foreach (var cell in range)
{
    Console.WriteLine("Cell {0} has value '{1}'", cell.RowIndex, cell.Value);
    if (cell.IsNumeric)
    {
        // Get decimal value to avoid floating numbers precision issue
        total += cell.DecimalValue;
    }
}

// Check formula evaluation
if (workSheet["A11"].DecimalValue == total)
{
    Console.WriteLine("Basic Test Passed");
}

Imports IronXL

Private workBook As WorkBook = WorkBook.Load("test.xlsx")
Private workSheet As WorkSheet = workBook.DefaultWorkSheet
Private range As IronXL.Range = workSheet("A2:A8")
Private total As Decimal = 0

' iterate over range of cells
For Each cell In range
	Console.WriteLine("Cell {0} has value '{1}'", cell.RowIndex, cell.Value)
	If cell.IsNumeric Then
		' Get decimal value to avoid floating numbers precision issue
		total += cell.DecimalValue
	End If
Next cell

' Check formula evaluation
If workSheet("A11").DecimalValue = total Then
	Console.WriteLine("Basic Test Passed")
End If

Write and Save Changes to the Excel File: Quick Code

:path=/static-assets/excel/content-code-examples/tutorials/csharp-open-write-excel-file-2.cs

workSheet["B1"].Value = 11.54;

// Save Changes
workBook.SaveAs("test.xlsx");

workSheet("B1").Value = 11.54

' Save Changes
workBook.SaveAs("test.xlsx")

Step 1

1. Install the IronXL C# Library FREE

Start using IronXL in your project today with a free trial.

First Step:

Start for Free

IronXL.Excel provides a flexible and powerful library for opening, reading, editing, and saving Excel files in .NET. It can be installed and used on all of the .NET project types, like Windows applications, ASP.NET MVC, and .NET Core Application.

Install the Excel Library to your Visual Studio Project with NuGet

The first step will be to install IronXL.Excel. To add the IronXL.Excel library to the project, we have two ways: NuGet Package Manager or NuGet Package Manager Console.

To add IronXL.Excel library to our project using NuGet, we can do it using a visualized interface, NuGet Package Manager:

1. Using mouse -> right-click on project name -> Select manage NuGet Package
2. From the browse tab -> search for IronXL.Excel -> Install
3. And we are done

Install Using NuGet Package Manager Console

1. From tools -> NuGet Package Manager -> Package Manager Console
2. Run command

Install-Package IronXL.Excel

Manually Install with the DLL

You may also choose to manually install the DLL to your project or to your global assembly cache.

How To Tutorials

2. Basic Operations: Create, Open, Save

2.1. Sample Project: HelloWorld Console Application

Create a HelloWorld Project in Visual Studio.

1. Open Visual Studio
2. Choose Create New Project
3. Choose Console App (.NET framework)
4. Give the sample the name “HelloWorld” and click create
5. Now the console application is created
6. Add IronXL.Excel to your project -> click install
7. Add code to read the first cell in the first sheet from an Excel file and print it

using IronXL;

var workbook = WorkBook.Load("example.xlsx");
var sheet = workbook.DefaultWorkSheet;
Console.WriteLine(sheet["A1"].Text);

using IronXL;

var workbook = WorkBook.Load("example.xlsx");
var sheet = workbook.DefaultWorkSheet;
Console.WriteLine(sheet["A1"].Text);

Imports IronXL

Private workbook = WorkBook.Load("example.xlsx")
Private sheet = workbook.DefaultWorkSheet
Console.WriteLine(sheet("A1").Text)

...

Further Reading

To learn more about working with IronXL, you may wish to look at other tutorials within this section and also the examples on our homepage, which most developers find sufficient to get started. Our API Reference contains specific references to the WorkBook class.

Chaknith Bin

  Chat with engineering team now

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.

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