Convert MHT to XLSX Using GroupDocs.Conversion in .NET

Introduction

If you’re working with email archive formats or web pages saved in MHT files, you might find yourself needing to convert these files into more usable formats like XLSX for data analysis, reporting, or further manipulation. That’s where GroupDocs.Conversion for .NET comes into play—an intuitive, powerful library that simplifies document conversions. In this guide, I’ll walk you through converting an MHT file into an XLSX spreadsheet step-by-step. You’ll learn what’s required, how to set everything up, and then see a clear breakdown of the conversion process.

Prerequisites

Before diving into the code, make sure you have the following in place:

  • .NET development environment (Visual Studio or similar)
  • GroupDocs.Conversion for .NET SDK (the library we’ll use for conversion)
  • A valid license (trial is fine for testing)
  • An MHT file to convert

Why Choose GroupDocs.Conversion?

It’s versatile, easy to implement, and supports multiple formats. Whether you want to convert documents, images, or email archives, GroupDocs makes it straightforward—no complex dependencies or command-line tools involved.

Import Packages

Start by importing the necessary GroupDocs libraries at the top of your C# file:

using GroupDocs.Conversion;
using GroupDocs.Conversion.Options.Convert;
using System.IO;

Ensure you have added the GroupDocs.Conversion DLL references to your project. If not, download the latest SDK from the official resources.

Step-by-Step Guide

Let’s walk through converting an MHT to XLSX in simple, digestible steps.

Step 1: Set up Your Output Directory

Why? Having a dedicated folder keeps your files organized, especially if you’re processing multiple conversions.

string outputFolder = @"C:\ConversionOutput"; // Change path as needed
if (!Directory.Exists(outputFolder))
{
    Directory.CreateDirectory(outputFolder);
}
string outputFile = Path.Combine(outputFolder, "mht-converted-to.xlsx");

This code snippet creates an output directory if it doesn’t exist and prepares the destination path for the converted file.

Step 2: Load Your Source MHT File

What’s happening? You’re loading the MHT file into the converter instance to prepare for conversion.

string sourceFilePath = @"C:\Path\To\Your\File.mht"; // Update file path
using (var converter = new Converter(sourceFilePath))
{
    // Conversion steps will be placed here
}

Make sure your actual MHT file path replaces the placeholder.

Step 3: Configure the Conversion Options

Why? Customizing options ensures your converted XLSX file looks and functions as you want.

var options = new SpreadsheetConvertOptions();

This sets up default options suitable for most needs. If you’re aiming for special formatting, you can tweak these options later.

Step 4: Perform the Conversion

This is it—the magic moment. Call the Convert() method with the destination path and options.

converter.Convert(outputFile, options);

Once you run this, GroupDocs handles the heavy lifting, transforming your MHT into an Excel XLSX file seamlessly.

Step 5: Confirm and Check Output

Add a simple message to confirm success.

Console.WriteLine($"Conversion successful! Check your output at {outputFolder}");

You can also programmatically check if the file exists.

Conclusion

Whether you’re archiving email data, web pages, or need to process MHT files for data analysis, GroupDocs.Conversion makes your job easy. Once set up, you can automate bulk conversions or integrate it into larger workflows, saving you time and reducing manual effort.

FAQs

Q1: Can I customize how the XLSX looks after conversion?

A: Yes, you can adjust SpreadsheetConvertOptions for formatting, paging, and other settings.

Q2: Does GroupDocs support converting other email formats?

A: Absolutely, it supports formats like EML, MSG, PST, and more.

Q3: Is the library free to use?

A: A free trial is available, but you’ll need a license for full features and production use.

Q4: Can I automate this process?

A: Yes! Once you have the code, you can schedule it via scripts, batch processes, or integrate into your app.

Q5: What are the system requirements?

A: Compatible with any Windows system with .NET Framework or .NET Core installed.

Resources

For further exploration and support: