How to Read Open Office Excel File in C# Without Excel Installed

What Makes Reading Excel Files Challenging Without Office Installed?

Traditional approaches using Microsoft.Office.Interop.Excel require Excel installed on every machine running your code. This creates significant problems for server deployments, cloud hosting, and automation scenarios where Excel installation isn't practical or permitted.

The Interop approach also introduces issues with COM object management, memory leaks, and licensing concerns. IronXL solves these problems by providing a standalone library that can read Excel files, write data, and handle formatting without any external dependencies. The API supports .NET Framework and modern .NET versions, making it ideal for both legacy and new projects.

How Can Developers Install and Set Up the Excel Library?

Installing IronXL takes seconds using NuGet Package Manager. Run this command in your project:

Install-Package IronXL.Excel

Here's a basic sample using the traditional class structure to load an Excel workbook:

using IronXL;
using System;
class Program
{
    static void Main(string[] args)
    {
        // Load Excel file - works with XLS and XLSX formats
        var workbook = WorkBook.Load("data.xlsx");
        // Access the first worksheet
        WorkSheet sheet = workbook.DefaultWorkSheet;
        // Read data from a specific cell
        string value = sheet["A1"].StringValue;
        Console.WriteLine($"Cell A1 contains: {value}");
        Console.WriteLine("Excel file read successfully!");
    }
}

using IronXL;
using System;
class Program
{
    static void Main(string[] args)
    {
        // Load Excel file - works with XLS and XLSX formats
        var workbook = WorkBook.Load("data.xlsx");
        // Access the first worksheet
        WorkSheet sheet = workbook.DefaultWorkSheet;
        // Read data from a specific cell
        string value = sheet["A1"].StringValue;
        Console.WriteLine($"Cell A1 contains: {value}");
        Console.WriteLine("Excel file read successfully!");
    }
}

How Do You Load and Read Excel Workbook Data?

IronXL makes it straightforward to read Excel files and extract information. The following example shows how to iterate through rows and cells:

using IronXL;
// Load the spreadsheet file
WorkBook workbook = WorkBook.Load("customers.xlsx");
WorkSheet worksheet = workbook.WorkSheets[0];
// Get the count of rows with data
int rowCount = worksheet.RowCount;
Console.WriteLine($"Total rows: {rowCount}");
// Iterate through rows and cells
foreach (var row in worksheet.Rows)
{
    foreach (var cell in row)
    {
        if (!cell.IsEmpty)
            Console.Write($"{cell.StringValue}\t");
    }
    Console.WriteLine();
}

using IronXL;
// Load the spreadsheet file
WorkBook workbook = WorkBook.Load("customers.xlsx");
WorkSheet worksheet = workbook.WorkSheets[0];
// Get the count of rows with data
int rowCount = worksheet.RowCount;
Console.WriteLine($"Total rows: {rowCount}");
// Iterate through rows and cells
foreach (var row in worksheet.Rows)
{
    foreach (var cell in row)
    {
        if (!cell.IsEmpty)
            Console.Write($"{cell.StringValue}\t");
    }
    Console.WriteLine();
}

How Can You Read Different Data Types from Cells?

Excel cells contain various data types including strings, numbers, dates, and formulas. IronXL provides typed value properties to handle each scenario:

using IronXL;
WorkBook workbook = WorkBook.Load("Inventory.xlsx");
WorkSheet sheet = workbook.GetWorkSheet("Products");
// Read different data types from cells
string productName = sheet["A2"].StringValue;
int quantity = sheet["B2"].IntValue;
decimal price = sheet["C2"].DecimalValue;
DateTime orderDate = sheet["D2"].DateTimeValue ?? DateTime.MinValue;
Console.WriteLine($"Product: {productName}");
Console.WriteLine($"Quantity: {quantity}, Price: {price:C}");
Console.WriteLine($"Order Date: {orderDate:d}");
// Save modified workbook if needed
workbook.SaveAs("updated_report.xlsx");

using IronXL;
WorkBook workbook = WorkBook.Load("Inventory.xlsx");
WorkSheet sheet = workbook.GetWorkSheet("Products");
// Read different data types from cells
string productName = sheet["A2"].StringValue;
int quantity = sheet["B2"].IntValue;
decimal price = sheet["C2"].DecimalValue;
DateTime orderDate = sheet["D2"].DateTimeValue ?? DateTime.MinValue;
Console.WriteLine($"Product: {productName}");
Console.WriteLine($"Quantity: {quantity}, Price: {price:C}");
Console.WriteLine($"Order Date: {orderDate:d}");
// Save modified workbook if needed
workbook.SaveAs("updated_report.xlsx");

How Does the Library Handle Merged Cells and Special Formatting?

Working with merged cells is common when processing spreadsheets with headers or grouped data. IronXL correctly reads values from merged cells regions:

using IronXL;
WorkBook workbook = WorkBook.Load("formatted_data.xlsx");
WorkSheet sheet = workbook.DefaultWorkSheet;
// Access merged cells - value exists in the top-left cell
string headerValue = sheet["A1"].StringValue;
// Check columns and formatting
int columnCount = sheet.ColumnCount;
Console.WriteLine($"Header: {headerValue}");
Console.WriteLine($"Columns: {columnCount}");
// Read CSV data alternatively
WorkBook csvWorkbook = WorkBook.Load("data.csv");
WorkSheet csvSheet = csvWorkbook.DefaultWorkSheet;
Console.WriteLine($"CSV rows imported: {csvSheet.RowCount}");

using IronXL;
WorkBook workbook = WorkBook.Load("formatted_data.xlsx");
WorkSheet sheet = workbook.DefaultWorkSheet;
// Access merged cells - value exists in the top-left cell
string headerValue = sheet["A1"].StringValue;
// Check columns and formatting
int columnCount = sheet.ColumnCount;
Console.WriteLine($"Header: {headerValue}");
Console.WriteLine($"Columns: {columnCount}");
// Read CSV data alternatively
WorkBook csvWorkbook = WorkBook.Load("data.csv");
WorkSheet csvSheet = csvWorkbook.DefaultWorkSheet;
Console.WriteLine($"CSV rows imported: {csvSheet.RowCount}");

What Are Best Practices for Server and Web Application Deployment?

Deploying Excel processing to a server or web applications requires no special configuration with IronXL. The library runs without Excel installed on the machine, making it perfect for Azure, AWS, Docker containers, and Linux servers.

For web applications, suggest implementing file processing asynchronously to avoid blocking user requests. The library is thread-safe and can handle multiple concurrent operations. You can create document processing pipelines, generate reports, and edit Excel files programmatically, all without worrying about Office automation limitations or macros execution.

IronXL supports XML-based XLSX files and legacy XLS formats equally well. Whether your users upload files from Microsoft Excel, OpenOffice, or other spreadsheet applications, the library processes them reliably.

Conclusion: Streamlining Your .NET Excel Workflow

Reading Open Office and Excel files in C# shouldn't require the overhead of a full Microsoft Office installation or the headaches of COM Interop. As we’ve explored, moving away from legacy dependencies allows you to build more robust, scalable, and platform-independent applications.

By using a dedicated library like IronXL, you eliminate common server-side hurdles, such as "stuck" background processes and licensing restrictions, while gaining the ability to deploy to Linux, Azure, and Docker with ease. Whether you are building a simple data importer or a complex automated reporting engine, the ability to handle various data types and cell formats programmatically ensures your application remains professional and reliable.

IronXL transforms how .NET developers work with spreadsheet files. The free trial lets you test all features in your development environment without restrictions. When ready for production, start your free trial or purchase a license to unlock the full potential of Excel file processing in your applications.

Get stated with IronXL now.

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