What is IronXL and how does it relate to Blazor?

IronXL is a powerful .NET Excel library that allows developers to work with Excel files in various formats, including CSV, without needing Microsoft Office or Excel Interop. It seamlessly integrates with Blazor applications to enable tasks like converting Excel data to CSV format.

Can I export Excel data to CSV using IronXL in a Blazor application?

Yes, you can use IronXL in a Blazor application to export Excel data to a CSV format. The tutorial explains how to set up a Blazor project, implement a file upload component, and use IronXL to handle file conversion.

What file formats does IronXL support for conversion in Blazor applications?

IronXL supports a range of Excel file formats, including XLS, XLSX, XLSM, XLTX, and CSV, making it versatile for various data conversion tasks in Blazor applications.

How do I install IronXL in my Blazor project?

To install IronXL in your Blazor project, open the Package Manager Console in Visual Studio and run the installation command. This prepares your project to use IronXL's functionalities.

What are the steps involved in uploading and converting an Excel file to CSV using Blazor and IronXL?

The process involves setting up a Blazor project, creating a file upload component with the `InputFile` element, reading the file into a memory stream, loading it with IronXL, and finally saving it as a CSV file.

What are the advantages of using IronXL for Excel operations in Blazor?

IronXL offers advanced features like reading, writing, and manipulating Excel files programmatically without Microsoft Office Interop, making it ideal for .NET applications like Blazor. It enhances productivity and broadens the scope of functionality in web applications.

How do I handle file conversion errors in a Blazor application using IronXL?

Error handling during file conversion can be managed using a try-catch block in the method responsible for handling file uploads and conversions. This ensures that any exceptions are caught, and appropriate error messages are displayed.

Is there a trial version available for IronXL, and what are the licensing options?

Yes, IronXL offers a free trial, allowing developers to test its features and capabilities before making a purchase. After the trial, licenses are available starting from the lite version, which offers broad access to its functionalities.

The C# Excel Library

Explore IronXL Excel Spreadsheet Library for C# .NET Start Free Trial

Read Excel Files without Interop

See All Code Examples

using IronXL;
using System;
using System.Linq;

// Supported for XLSX, XLS, XLSM, XLTX, CSV and TSV
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Select worksheet at index 0
WorkSheet workSheet = workBook.WorkSheets[0];

// Get any existing worksheet
WorkSheet firstSheet = workBook.DefaultWorkSheet;

// Select a cell and return the converted value
int cellValue = workSheet["A2"].IntValue;

// Read from ranges of cells elegantly.
foreach (var cell in workSheet["A2:A10"])
{
    Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text);
}

// Calculate aggregate values such as Min, Max and Sum
decimal sum = workSheet["A2:A10"].Sum();

// Linq compatible
decimal max = workSheet["A2:A10"].Max(c => c.DecimalValue);

using IronXL;
using System;
using System.Linq;

// Supported for XLSX, XLS, XLSM, XLTX, CSV and TSV
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Select worksheet at index 0
WorkSheet workSheet = workBook.WorkSheets[0];

// Get any existing worksheet
WorkSheet firstSheet = workBook.DefaultWorkSheet;

// Select a cell and return the converted value
int cellValue = workSheet["A2"].IntValue;

// Read from ranges of cells elegantly.
foreach (var cell in workSheet["A2:A10"])
{
    Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text);
}

// Calculate aggregate values such as Min, Max and Sum
decimal sum = workSheet["A2:A10"].Sum();

// Linq compatible
decimal max = workSheet["A2:A10"].Max(c => c.DecimalValue);

PM >Install-Package IronXL.Excel

Install-Package IronXL.Excel

USING IRONXL

How to Export to CSV in Blazor

Curtis Chau

Updated: April 21, 2026

Today, we're diving into how to use Blazor and IronXL to convert an Excel file to CSV format. By the end of this tutorial, you'll be able to create a basic Blazor application that exports Excel data in various formats, including CSV.

Introduction to IronXL

IronXL is a powerful .NET Excel library designed to work with Excel files in a wide range of formats, including XLS, XLSX, XLSM, XLTX, and CSV. It allows developers to read, write, and manipulate Excel data programmatically without the need for Microsoft Office or Excel Interop.

With IronXL, you can create, load, and save Excel workbooks, as well as read and write data to individual cells or ranges. It also supports advanced features such as formatting, formulas, charts, and pivot tables. IronXL is compatible with various .NET Frameworks and can be used with popular languages like C# and VB.NET.

Steps to Convert Excel File to CSV

Setting Up Your Blazor Project

To get started, you'll need to create a new Blazor Server project. Open Visual Studio, create a new project and select the "Blazor Server App" template. Name your project, and click "Create."

Once your project is created, open the Pages folder and locate the Index.razor file. This is where the Blazor components are added and coded to handle file uploads and conversions.

Installing IronXL

Before starting to write code, it is necessary to install the IronXL library. Open the Package Manager Console in Visual Studio and run the following command:

PM > Install-Package IronXL.Excel

Install-Package IronXL.Excel

This command will install the IronXL library in your Blazor project. Now you're ready to start writing code!

Creating the File Upload Component

First, create a basic file upload component that allows users to upload an existing Excel file. Then, the InputFile component is added from the Microsoft.AspNetCore.Components.Forms namespace. Add the following code to your Index.razor file, below the "@page """ line:

@using Microsoft.AspNetCore.Components.Forms
@using IronXL
@using System.IO
@using System.Threading.Tasks

<div class="container">
    <h3>File Upload</h3>

    <InputFile class="button" OnChange="@OnInputFileChange" accept=".xls,.xlsx,.xlsm,.xltx,.csv,.tsv" />
    <h3>Selected File: @originalFileName</h3>
    <h3 style="color:bisque">Is File converted: <span>@message</span></h3>
</div>

@using Microsoft.AspNetCore.Components.Forms
@using IronXL
@using System.IO
@using System.Threading.Tasks

<div class="container">
    <h3>File Upload</h3>

    <InputFile class="button" OnChange="@OnInputFileChange" accept=".xls,.xlsx,.xlsm,.xltx,.csv,.tsv" />
    <h3>Selected File: @originalFileName</h3>
    <h3 style="color:bisque">Is File converted: <span>@message</span></h3>
</div>

Text

This code sets up the file upload component, complete with a button and a message area to display the status of the file conversion. The accept attribute on the InputFile component specifies the accepted file formats.

Writing the File Conversion Code

Now, let's write the code that handles the file upload and conversion. A combination of IronXL, Blazor, and C# will be used to accomplish this task. You can use IronXL to convert a CSV to an Excel file.

Add the following code to your Index.razor file, below the div element you added earlier.

@code {
    private string originalFileName;
    private string message = "";

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        var file = e.File;
        originalFileName = file.Name;

        try
        {
            // Read the uploaded file into a memory stream
            using var memoryStream = new MemoryStream();
            await file.OpenReadStream().CopyToAsync(memoryStream);

            // Load the workbook using IronXL
            WorkBook workBook = WorkBook.Load(memoryStream);

            // Save the workbook as a CSV file
            string outputPath = "sample.csv";
            workBook.SaveAsCsv(outputPath);

            message = "Conversion completed!";
        }
        catch (Exception ex)
        {
            message = $"An error occurred: {ex.Message}";
        }
    }
}

@code {
    private string originalFileName;
    private string message = "";

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        var file = e.File;
        originalFileName = file.Name;

        try
        {
            // Read the uploaded file into a memory stream
            using var memoryStream = new MemoryStream();
            await file.OpenReadStream().CopyToAsync(memoryStream);

            // Load the workbook using IronXL
            WorkBook workBook = WorkBook.Load(memoryStream);

            // Save the workbook as a CSV file
            string outputPath = "sample.csv";
            workBook.SaveAsCsv(outputPath);

            message = "Conversion completed!";
        }
        catch (Exception ex)
        {
            message = $"An error occurred: {ex.Message}";
        }
    }
}

Text

This code defines a private method called OnInputFileChange, which will be triggered when an Excel spreadsheet is uploaded using the InputFile component; Excel can be in XLS or XLSX format. The code reads the uploaded basic Excel file, loads it into a WorkBook object, and then saves the WorkBook as a CSV file. The status of the conversion is displayed in the message area on the page.

Code Breakdown

First, look at the complete code:

@page "/"
@using Microsoft.AspNetCore.Components.Forms
@using IronXL
@using System.IO
@using System.Threading.Tasks

<style>
    body{
        background-color: skyblue
    }
    .container {
        max-width: 800px;
        margin: 0 auto;
        font-family: Arial, sans-serif;
    }

    h3 {
        margin-top: 30px;
        font-size: 30px;
        margin-bottom: 30px;
    }

    .button {
        background-color: #4CAF50;
        border: none;
        color: white;
        padding: 15px 32px;
        text-align: center;
        text-decoration: none;
        display: inline-block;
        font-size: 16px;
        margin: 15px 0;
        cursor: pointer;
    }
    span {
        font-size: 20px;
    }
</style>

<div class="container">
    <h3>File Upload</h3>

    <InputFile class="button" OnChange="@OnInputFileChange" accept=".xls,.xlsx,.xlsm,.xltx,.csv,.tsv" />
    <h3>Selected File: @originalFileName</h3>
    <h3 style="color:bisque">Is File converted: <span>@message</span></h3>
</div>

@code {
    private string originalFileName;
    private string message = "";

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        var file = e.File;
        originalFileName = file.Name;

        try
        {
            // Read the uploaded file into a memory stream
            using var memoryStream = new MemoryStream();
            await file.OpenReadStream().CopyToAsync(memoryStream);

            // Load the workbook using IronXL
            WorkBook workBook = WorkBook.Load(memoryStream);

            // Save the workbook as a CSV file
            string outputPath = "sample.csv";
            workBook.SaveAsCsv(outputPath);

            message = "Conversion completed!";
        }
        catch (Exception ex)
        {
            message = $"An error occurred: {ex.Message}";
        }
    }
}

@page "/"
@using Microsoft.AspNetCore.Components.Forms
@using IronXL
@using System.IO
@using System.Threading.Tasks

<style>
    body{
        background-color: skyblue
    }
    .container {
        max-width: 800px;
        margin: 0 auto;
        font-family: Arial, sans-serif;
    }

    h3 {
        margin-top: 30px;
        font-size: 30px;
        margin-bottom: 30px;
    }

    .button {
        background-color: #4CAF50;
        border: none;
        color: white;
        padding: 15px 32px;
        text-align: center;
        text-decoration: none;
        display: inline-block;
        font-size: 16px;
        margin: 15px 0;
        cursor: pointer;
    }
    span {
        font-size: 20px;
    }
</style>

<div class="container">
    <h3>File Upload</h3>

    <InputFile class="button" OnChange="@OnInputFileChange" accept=".xls,.xlsx,.xlsm,.xltx,.csv,.tsv" />
    <h3>Selected File: @originalFileName</h3>
    <h3 style="color:bisque">Is File converted: <span>@message</span></h3>
</div>

@code {
    private string originalFileName;
    private string message = "";

    private async Task OnInputFileChange(InputFileChangeEventArgs e)
    {
        var file = e.File;
        originalFileName = file.Name;

        try
        {
            // Read the uploaded file into a memory stream
            using var memoryStream = new MemoryStream();
            await file.OpenReadStream().CopyToAsync(memoryStream);

            // Load the workbook using IronXL
            WorkBook workBook = WorkBook.Load(memoryStream);

            // Save the workbook as a CSV file
            string outputPath = "sample.csv";
            workBook.SaveAsCsv(outputPath);

            message = "Conversion completed!";
        }
        catch (Exception ex)
        {
            message = $"An error occurred: {ex.Message}";
        }
    }
}

Text

Let's break down the code further:

When a file is uploaded, the OnInputFileChange method is triggered, and an InputFileChangeEventArgs object is passed to it. This object contains information about the uploaded file, such as its name and size.
Store the original file name in a variable called originalFileName to display it on the page.
Inside a try-catch block, create a new MemoryStream object to read the uploaded file's contents. The using statement ensures that the memory stream is properly disposed of once it's no longer needed.
Use the await keyword to asynchronously copy the contents of the uploaded file into the memory stream. This ensures that this application remains responsive while reading the file.
Next, the WorkBook.Load method is used to load the contents of the memory stream into a WorkBook object. This object represents the entire Excel workbook, including its sheets, cells, and data.
Then specify an output file name for the converted CSV file. In this case, we're using the name "sample.csv."
The SaveAsCsv method of the WorkBook object is then used to save the workbook as a CSV file with the specified output file name.
If the conversion is successful, a message is displayed to indicate that the conversion has been completed. If an error occurs, catch the exception and display an error message.

Testing the Application

Now that the Blazor application is complete, it's time to test it! Press F5 to run your application in Visual Studio. Once the application is running, you should see a file upload button on the page.

How to Export to CSV in Blazor, Figure 1: Run the Blazor application Run the Blazor application

Click the button, and select an Excel file to upload. The accepted file formats are listed in the accept attribute of the InputFile component.

How to Export to CSV in Blazor, Figure 2: Select an Excel file Select an Excel file

After you've selected a file, the application will read the file, convert it to a CSV format using IronXL, and save the converted file with the specified output file name. You should see a message indicating the status of the conversion, as well as the original file name.

How to Export to CSV in Blazor, Figure 3: Conversion status Conversion status

Congratulations! You've successfully built a Blazor application that can export Excel files to CSV format using IronXL. The following screenshot shows the output of the above program.

How to Export to CSV in Blazor, Figure 4: The output Excel file The output Excel file

Conclusion

This tutorial demonstrated how to build a Blazor application that can export Excel files to CSV format using IronXL. We've demonstrated how to create a file upload component, handle file uploads, and convert Excel files to CSV format using IronXL's powerful features.

By incorporating IronXL into your Blazor applications, you can easily handle a variety of Excel-related tasks, such as importing, manipulating, and exporting data. This opens up a wide range of possibilities for your projects and helps you provide a richer experience for your users. You can convert CSV to Excel in Blazor using the IronXL library.

IronXL offers a free trial, allowing you to test its features and capabilities before committing to a purchase. After the trial period, licenses for IronXL start at $999.

Curtis Chau

Chat with engineering team now

Technical Writer

Curtis Chau holds a Bachelor’s degree in Computer Science (Carleton University) and specializes in front-end development with expertise in Node.js, TypeScript, JavaScript, and React. Passionate about crafting intuitive and aesthetically pleasing user interfaces, Curtis enjoys working with modern frameworks and creating well-structured, visually appealing manuals.

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