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How to Export to Excel in a Blazor Using IronXL

Jordi Bardia
Jordi Bardia
Updated:

Exporting data to Excel is something almost every web app needs, whether it’s for generating reports, inventory lists, or customer invoices. In a Blazor Server application, reliably accomplishing this without requiring Microsoft Office can be challenging. That’s where IronXL comes in. It allows you to create, format, and download Excel files directly from your server, with no Office installation required, and integrates seamlessly with Blazor. In this guide, you’ll see just how simple it is to add professional Excel export features to your app. Let's get started.

Getting Started with IronXL to Export Data to Excel

Setting up IronXL in a Blazor Server application requires minimal configuration. Start by creating a new Blazor Server project in Visual Studio 2022 or later, targeting .NET 6 or above.

Install IronXL through the NuGet Package Manager Console (see our complete installation guide for alternative methods):

Install-Package IronXL.Excel

Next, create a JavaScript helper function for file downloads. In your wwwroot folder, add a new JavaScript file called excelExport.js:

window.downloadFileFromStream = async (fileName, contentStreamReference) => {
    const arrayBuffer = await contentStreamReference.arrayBuffer();
    const blob = new Blob([arrayBuffer]);
    const url = URL.createObjectURL(blob);
    const anchorElement = document.createElement('a');
    anchorElement.href = url;
    anchorElement.download = fileName ?? 'export.xlsx';
    anchorElement.click();
    anchorElement.remove();
    URL.revokeObjectURL(url);
}
window.downloadFileFromStream = async (fileName, contentStreamReference) => {
    const arrayBuffer = await contentStreamReference.arrayBuffer();
    const blob = new Blob([arrayBuffer]);
    const url = URL.createObjectURL(blob);
    const anchorElement = document.createElement('a');
    anchorElement.href = url;
    anchorElement.download = fileName ?? 'export.xlsx';
    anchorElement.click();
    anchorElement.remove();
    URL.revokeObjectURL(url);
}
JAVASCRIPT

Include this script in your _Host.cshtml file:

<script src="~/excelExport.js"></script>
<script src="~/excelExport.js"></script>
HTML

This JavaScript function handles the browser-side download mechanism, converting the byte stream from your Blazor Server application into a downloadable file. The function creates a temporary blob URL, triggers the download, and cleans up resources to prevent memory leaks.

How to Export a Data Source to Excel Files with IronXL?

Create an Excel export service to handle your business logic. This service encapsulates IronXL functionality and provides reusable methods for different export scenarios in your Blazor Excel export implementation:

using IronXL;
using System.IO;
using ExportExcel.Models;
public class ExcelExportService
{
    public byte[] GenerateSalesReport(List<SalesData> salesData)
    {
        try
        {
            var workbook = WorkBook.Create(ExcelFileFormat.XLSX);
            workbook.Metadata.Author = "Sales Department";
            var worksheet = workbook.CreateWorkSheet("Monthly Sales");
            worksheet["A1"].Value = "Date";
            worksheet["B1"].Value = "Product";
            worksheet["C1"].Value = "Quantity";
            worksheet["D1"].Value = "Revenue";
            worksheet["E1"].Value = "Profit Margin";
            var headerRange = worksheet["A1:E1"];
            headerRange.Style.Font.Bold = true;
            headerRange.Style.BackgroundColor = "#4472C4";
            headerRange.Style.Font.Color = "#FFFFFF";
            int row = 2;
            foreach (var sale in salesData)
            {
                worksheet[$"A{row}"].Value = sale.Date.ToString("yyyy-MM-dd");
                worksheet[$"B{row}"].Value = sale.Product ?? "Unknown";
                worksheet[$"C{row}"].Value = sale.Quantity;
                worksheet[$"D{row}"].Value = sale.Revenue;
                worksheet[$"E{row}"].Value = $"=D{row}*0.15";
                row++;
            }
            worksheet.AutoSizeColumn(0, true);
            using var ms = workbook.ToStream();
            return ms.ToArray();
        }
        catch (Exception ex)
        {
        // If the program fails to return file
            throw new InvalidOperationException("Failed to generate sales report", ex);
        }
    }
}
using IronXL;
using System.IO;
using ExportExcel.Models;
public class ExcelExportService
{
    public byte[] GenerateSalesReport(List<SalesData> salesData)
    {
        try
        {
            var workbook = WorkBook.Create(ExcelFileFormat.XLSX);
            workbook.Metadata.Author = "Sales Department";
            var worksheet = workbook.CreateWorkSheet("Monthly Sales");
            worksheet["A1"].Value = "Date";
            worksheet["B1"].Value = "Product";
            worksheet["C1"].Value = "Quantity";
            worksheet["D1"].Value = "Revenue";
            worksheet["E1"].Value = "Profit Margin";
            var headerRange = worksheet["A1:E1"];
            headerRange.Style.Font.Bold = true;
            headerRange.Style.BackgroundColor = "#4472C4";
            headerRange.Style.Font.Color = "#FFFFFF";
            int row = 2;
            foreach (var sale in salesData)
            {
                worksheet[$"A{row}"].Value = sale.Date.ToString("yyyy-MM-dd");
                worksheet[$"B{row}"].Value = sale.Product ?? "Unknown";
                worksheet[$"C{row}"].Value = sale.Quantity;
                worksheet[$"D{row}"].Value = sale.Revenue;
                worksheet[$"E{row}"].Value = $"=D{row}*0.15";
                row++;
            }
            worksheet.AutoSizeColumn(0, true);
            using var ms = workbook.ToStream();
            return ms.ToArray();
        }
        catch (Exception ex)
        {
        // If the program fails to return file
            throw new InvalidOperationException("Failed to generate sales report", ex);
        }
    }
}
Imports IronXL
Imports System.IO
Imports ExportExcel.Models

Public Class ExcelExportService
    Public Function GenerateSalesReport(salesData As List(Of SalesData)) As Byte()
        Try
            Dim workbook = WorkBook.Create(ExcelFileFormat.XLSX)
            workbook.Metadata.Author = "Sales Department"
            Dim worksheet = workbook.CreateWorkSheet("Monthly Sales")
            worksheet("A1").Value = "Date"
            worksheet("B1").Value = "Product"
            worksheet("C1").Value = "Quantity"
            worksheet("D1").Value = "Revenue"
            worksheet("E1").Value = "Profit Margin"
            Dim headerRange = worksheet("A1:E1")
            headerRange.Style.Font.Bold = True
            headerRange.Style.BackgroundColor = "#4472C4"
            headerRange.Style.Font.Color = "#FFFFFF"
            Dim row As Integer = 2
            For Each sale In salesData
                worksheet($"A{row}").Value = sale.Date.ToString("yyyy-MM-dd")
                worksheet($"B{row}").Value = If(sale.Product, "Unknown")
                worksheet($"C{row}").Value = sale.Quantity
                worksheet($"D{row}").Value = sale.Revenue
                worksheet($"E{row}").Value = $"=D{row}*0.15"
                row += 1
            Next
            worksheet.AutoSizeColumn(0, True)
            Using ms = workbook.ToStream()
                Return ms.ToArray()
            End Using
        Catch ex As Exception
            ' If the program fails to return file
            Throw New InvalidOperationException("Failed to generate sales report", ex)
        End Try
    End Function
End Class
$vbLabelText   $csharpLabel

This service demonstrates key IronXL features, including creating new workbooks and worksheets, adding formatted headers, populating data rows with imported data from your data source, applying formulas, and handling potential errors. The AutoSizeColumn method ensures that columns display properly, regardless of the content length. For more advanced formatting options, explore our cell styling guide.

How Do You Implement the File Download in Blazor?

Create a Razor component that uses the export service and handles user interaction:

@page "/excel-export"
@using ExportExcel.Models
@inject ExcelExportService ExcelService
@inject IJSRuntime JS
<h3>Excel Export Dashboard</h3>
<div class="export-section">
    <button class="btn btn-primary" @onclick="ExportSalesReport" disabled="@isExporting">
        @if (isExporting)
        {
            <span>Generating...</span>
        }
        else
        {
            <span>Export Sales Report</span>
        }
    </button>
    @if (!string.IsNullOrEmpty(errorMessage))
    {
        <div class="alert alert-danger mt-2">@errorMessage</div>
    }
</div>
@code {
    private bool isExporting = false;
    private string errorMessage = "";
    private async Task ExportSalesReport()
    {
        try
        {
            isExporting = true;
            errorMessage = "";
            // Generate sample data - replace with actual data source
            var salesData = GetSalesData();
            // Generate Excel file
            var fileBytes = ExcelService.GenerateSalesReport(salesData);
            // Trigger download using a memory stream to handle the file
            using var stream = new MemoryStream(fileBytes);
            using var streamRef = new DotNetStreamReference(stream);
            await JS.InvokeVoidAsync("downloadFileFromStream",
                $"SalesReport_{DateTime.Now:yyyyMMdd}.xlsx", streamRef);
        }
        catch (Exception ex)
        {
            errorMessage = "Export failed. Please try again.";
            // Log exception details for debugging
        }
        finally
        {
            isExporting = false;
        }
    }
    private List<SalesData> GetSalesData()
    {
        // Return your actual data here
        return new List<SalesData>
        {
            new() { Date = DateTime.Now, Product = "Widget A",
                   Quantity = 100, Revenue = 5000 },
            new() { Date = DateTime.Now.AddDays(-1), Product = "Widget B",
                   Quantity = 75, Revenue = 3750 }
        };
    }
}
@page "/excel-export"
@using ExportExcel.Models
@inject ExcelExportService ExcelService
@inject IJSRuntime JS
<h3>Excel Export Dashboard</h3>
<div class="export-section">
    <button class="btn btn-primary" @onclick="ExportSalesReport" disabled="@isExporting">
        @if (isExporting)
        {
            <span>Generating...</span>
        }
        else
        {
            <span>Export Sales Report</span>
        }
    </button>
    @if (!string.IsNullOrEmpty(errorMessage))
    {
        <div class="alert alert-danger mt-2">@errorMessage</div>
    }
</div>
@code {
    private bool isExporting = false;
    private string errorMessage = "";
    private async Task ExportSalesReport()
    {
        try
        {
            isExporting = true;
            errorMessage = "";
            // Generate sample data - replace with actual data source
            var salesData = GetSalesData();
            // Generate Excel file
            var fileBytes = ExcelService.GenerateSalesReport(salesData);
            // Trigger download using a memory stream to handle the file
            using var stream = new MemoryStream(fileBytes);
            using var streamRef = new DotNetStreamReference(stream);
            await JS.InvokeVoidAsync("downloadFileFromStream",
                $"SalesReport_{DateTime.Now:yyyyMMdd}.xlsx", streamRef);
        }
        catch (Exception ex)
        {
            errorMessage = "Export failed. Please try again.";
            // Log exception details for debugging
        }
        finally
        {
            isExporting = false;
        }
    }
    private List<SalesData> GetSalesData()
    {
        // Return your actual data here
        return new List<SalesData>
        {
            new() { Date = DateTime.Now, Product = "Widget A",
                   Quantity = 100, Revenue = 5000 },
            new() { Date = DateTime.Now.AddDays(-1), Product = "Widget B",
                   Quantity = 75, Revenue = 3750 }
        };
    }
}
@page "/excel-export"
@Imports ExportExcel.Models
@inject ExcelExportService ExcelService
@inject IJSRuntime JS
<h3>Excel Export Dashboard</h3>
<div class="export-section">
    <button class="btn btn-primary" @onclick="ExportSalesReport" disabled="@isExporting">
        @If isExporting Then
            <span>Generating...</span>
        Else
            <span>Export Sales Report</span>
        End If
    </button>
    @If Not String.IsNullOrEmpty(errorMessage) Then
        <div class="alert alert-danger mt-2">@errorMessage</div>
    End If
</div>
@code {
    Private isExporting As Boolean = False
    Private errorMessage As String = ""
    Private Async Function ExportSalesReport() As Task
        Try
            isExporting = True
            errorMessage = ""
            ' Generate sample data - replace with actual data source
            Dim salesData = GetSalesData()
            ' Generate Excel file
            Dim fileBytes = ExcelService.GenerateSalesReport(salesData)
            ' Trigger download using a memory stream to handle the file
            Using stream As New MemoryStream(fileBytes)
                Using streamRef As New DotNetStreamReference(stream)
                    Await JS.InvokeVoidAsync("downloadFileFromStream", $"SalesReport_{DateTime.Now:yyyyMMdd}.xlsx", streamRef)
                End Using
            End Using
        Catch ex As Exception
            errorMessage = "Export failed. Please try again."
            ' Log exception details for debugging
        Finally
            isExporting = False
        End Try
    End Function

    Private Function GetSalesData() As List(Of SalesData)
        ' Return your actual data here
        Return New List(Of SalesData) From {
            New SalesData With {.Date = DateTime.Now, .Product = "Widget A", .Quantity = 100, .Revenue = 5000},
            New SalesData With {.Date = DateTime.Now.AddDays(-1), .Product = "Widget B", .Quantity = 75, .Revenue = 3750}
        }
    End Function
}
$vbLabelText   $csharpLabel

This component provides user feedback during export, handles errors gracefully, and generates timestamped filenames. The DotNetStreamReference wrapper enables efficient streaming of binary data to JavaScript.

Output

When we run our code, we will see our page loaded with the button that will be used to handle the exporting process.

How to Export to Excel in a Blazor Using IronXL: Figure 1 - Sample Blazor page

When we click the button, the data will be saved in a new Excel document, and the exported file will be downloaded.

How to Export to Excel in a Blazor Using IronXL: Figure 2 - Data exported to an Excel file

What Advanced Features Can IronXL Add to Your Excel Export?

IronXL supports sophisticated Excel features for professional-looking exports. For an inventory management scenario, you might add conditional formatting and multiple worksheets:

using IronXL;
using ExportExcel.Models;
using System.IO;
namespace ExportExcel.Services
{
    public class InventoryExportService
    {
        public byte[] GenerateInventoryReport(List<InventoryItem> items)
        {
            var workbook = WorkBook.Create();
            var details = workbook.CreateWorkSheet("Inventory Details");
            // Add headers
            details["A1"].Value = "SKU";
            details["B1"].Value = "Name";
            details["C1"].Value = "Quantity";
            // Apply bold font for headers
            var headerRange = details["A1:C1"];
            headerRange.Style.Font.Bold = true;
            for (int i = 0; i < items.Count; i++)
            {
                var row = i + 2; // start from row 2
                var item = items[i];
                details[$"A{row}"].Value = item.SKU;
                details[$"B{row}"].Value = item.Name;
                details[$"C{row}"].Value = item.Quantity;
                // Highlight low stock items
                if (item.Quantity < item.ReorderLevel)
                {
                    details[$"C{row}"].Style.BackgroundColor = "#FFB6B6";
                }
            }
            using var stream = workbook.ToStream();
            return stream.ToArray();
        }
    }
}
using IronXL;
using ExportExcel.Models;
using System.IO;
namespace ExportExcel.Services
{
    public class InventoryExportService
    {
        public byte[] GenerateInventoryReport(List<InventoryItem> items)
        {
            var workbook = WorkBook.Create();
            var details = workbook.CreateWorkSheet("Inventory Details");
            // Add headers
            details["A1"].Value = "SKU";
            details["B1"].Value = "Name";
            details["C1"].Value = "Quantity";
            // Apply bold font for headers
            var headerRange = details["A1:C1"];
            headerRange.Style.Font.Bold = true;
            for (int i = 0; i < items.Count; i++)
            {
                var row = i + 2; // start from row 2
                var item = items[i];
                details[$"A{row}"].Value = item.SKU;
                details[$"B{row}"].Value = item.Name;
                details[$"C{row}"].Value = item.Quantity;
                // Highlight low stock items
                if (item.Quantity < item.ReorderLevel)
                {
                    details[$"C{row}"].Style.BackgroundColor = "#FFB6B6";
                }
            }
            using var stream = workbook.ToStream();
            return stream.ToArray();
        }
    }
}
Imports IronXL
Imports ExportExcel.Models
Imports System.IO

Namespace ExportExcel.Services
    Public Class InventoryExportService
        Public Function GenerateInventoryReport(items As List(Of InventoryItem)) As Byte()
            Dim workbook = WorkBook.Create()
            Dim details = workbook.CreateWorkSheet("Inventory Details")
            ' Add headers
            details("A1").Value = "SKU"
            details("B1").Value = "Name"
            details("C1").Value = "Quantity"
            ' Apply bold font for headers
            Dim headerRange = details("A1:C1")
            headerRange.Style.Font.Bold = True
            For i As Integer = 0 To items.Count - 1
                Dim row = i + 2 ' start from row 2
                Dim item = items(i)
                details($"A{row}").Value = item.SKU
                details($"B{row}").Value = item.Name
                details($"C{row}").Value = item.Quantity
                ' Highlight low stock items
                If item.Quantity < item.ReorderLevel Then
                    details($"C{row}").Style.BackgroundColor = "#FFB6B6"
                End If
            Next
            Using stream = workbook.ToStream()
                Return stream.ToArray()
            End Using
        End Function
    End Class
End Namespace
$vbLabelText   $csharpLabel

IronXL handles multiple worksheets effortlessly, applies conditional formatting based on business rules, and supports advanced Excel features, such as pivot tables and charts, when needed. For detailed API documentation, visit our comprehensive reference guide.

How to Export to Excel in a Blazor Using IronXL: Figure 3 - Advanced features example output

Conclusion

IronXL transforms Excel file generation in Blazor Server applications from a complex challenge into a straightforward task. Its intuitive API eliminates the need for Microsoft Office installations while providing access to advanced Excel features. From simple data exports to complex multi-sheet reports with formulas and formatting, IronXL handles it all with excellent performance and reliability.

Ready to enhance your Blazor applications with professional Excel export capabilities? Start your free trial for production deployment.

Frequently Asked Questions

How can I export Excel files in a Blazor Server app?

You can use IronXL to export Excel files in a Blazor Server app. IronXL allows you to create, format, and download Excel files directly from your server without the need for Microsoft Office.

Do I need Microsoft Office to work with Excel files in Blazor?

No, IronXL enables you to work with Excel files without requiring Microsoft Office. It provides the functionality to create and manipulate Excel files directly within your Blazor application.

What are the benefits of using IronXL for Excel export in Blazor?

IronXL offers seamless integration with Blazor, allowing you to easily create, format, and export Excel files. It simplifies the process, eliminates the need for Microsoft Office, and supports various Excel formats.

Can IronXL integrate with other Blazor components?

Yes, IronXL integrates seamlessly with Blazor components, enabling you to add Excel export functionality to your applications with ease.

Is it possible to format Excel files using IronXL in Blazor?

Yes, IronXL provides comprehensive features to format Excel files, including styling cells, adjusting column widths, and setting up complex formulas, all within your Blazor Server application.

How do you handle large datasets when exporting to Excel in Blazor?

IronXL is designed to efficiently handle large datasets, ensuring smooth performance when exporting extensive data to Excel files in a Blazor Server environment.

What Excel file formats are supported by IronXL?

IronXL supports various Excel file formats, including XLS, XLSX, and CSV, allowing flexibility in how you export and work with Excel data in your Blazor applications.

Can IronXL be used for generating reports in Blazor?

Absolutely, IronXL is ideal for generating detailed reports in Blazor applications. It offers robust features to compile, format, and export data into professional Excel reports.

How does IronXL ensure data integrity when exporting Excel files?

IronXL ensures data integrity by accurately preserving the structure and formatting of your data during the export process, making it a reliable solution for Blazor applications.

Is there a way to automate Excel file creation in a Blazor Server app using IronXL?

Yes, IronXL can be used to automate the creation and export of Excel files in Blazor Server apps, allowing you to streamline workflows and improve efficiency.

Jordi Bardia
Jordi Bardia
  Chat with engineering team now
Software Engineer
Jordi is most proficient in Python, C# and C++, when he isn’t leveraging his skills at Iron Software; he’s game programming. Sharing responsibilities for product testing, product development and research, Jordi adds immense value to continual product improvement. The varied experience keeps him challenged and engaged, and he ...
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