Compare Word Documents in ASP.NET Core

_layout.cshtml

<!--drag and drop file plugin-->
<link href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-fileinput/5.0.9/css/fileinput.min.css" media="all" rel="stylesheet" type="text/css" />
<script src="https://code.jquery.com/jquery-3.3.1.min.js" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.bundle.min.js" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-fileinput/5.0.9/js/fileinput.min.js"></script> 
<!--end of drag and drop-->

HomeController.cs

[HttpPost]
public FileResult UploadFiles(List<IFormFile> files, string outputFormat)
{
	if(files.Count()==0)
	{
		return null;
	}
	string fileName = "result.docx";
	// Upload files
	var file1 = Path.Combine("wwwroot/uploads", files[0].FileName);
	var file2 = Path.Combine("wwwroot/uploads", files[1].FileName);
	using (var stream = new FileStream(file1, FileMode.Create))
	{
		files[0].CopyTo(stream);
	}
	using (var stream = new FileStream(file2, FileMode.Create))
	{
		files[1].CopyTo(stream);
	}
	// Load Word documents
	Document doc1 = new Document(file1);
	Document doc2 = new Document(file2);
	// Set comparison features
	CompareOptions compareOptions = new CompareOptions();
	compareOptions.IgnoreFormatting = true;
	compareOptions.IgnoreCaseChanges = true;
	compareOptions.IgnoreComments = true;
	compareOptions.IgnoreTables = true;
	compareOptions.IgnoreFields = true;
	compareOptions.IgnoreFootnotes = true;
	compareOptions.IgnoreTextboxes = true;
	compareOptions.IgnoreHeadersAndFooters = true;
	compareOptions.Target = ComparisonTargetType.New;

	var outputStream = new MemoryStream();
	// Compare Word documents
	doc1.Compare(doc2, "John Doe", DateTime.Now, compareOptions);
	if (outputFormat == "DOCX")
	{
		// For comparison result in DOCX
		doc1.Save(outputStream, SaveFormat.Docx);
		outputStream.Position = 0;
		// Return generated Word file
		return File(outputStream, System.Net.Mime.MediaTypeNames.Application.Rtf, fileName);
	}
	else
	{
		// For comparison result in PDF
		fileName = "result.pdf";
		doc1.Save(outputStream, SaveFormat.Pdf);
		outputStream.Position = 0;
		// Return generated PDF file
		return File(outputStream, System.Net.Mime.MediaTypeNames.Application.Pdf, fileName);
	}    
}

index.cshtml

@{
    ViewData["Title"] = "MS Word Comparison in ASP.NET";
}
<h2 class="text-info">Compare Two Word DOC/DOCX Documents</h2>
<p class="text-info">Compare the contents of MS Word documents and get the results in DOCX or PDF format.</p>
<br />
<form asp-controller="Home" asp-action="UploadFiles" method="post" class="form-inline dropzone" enctype="multipart/form-data">
    <div class="row">
        <div class="col-md-6" align="center"> 
            <div class="form-group">
                <input type="file" id="input-id" name="files" accept=".doc, .docx" class="form-control file" data-preview-file-type="text" />
            </div>
        </div>
        <div class="col-md-6" align="center"> 
            <div class="form-group">
                <input type="file" id="input-id2" name="files" accept=".doc, .docx" class="form-control file" />
            </div>
        </div>
    </div>
    <br />
    <div class="row">
        <div class="col-md-12" align="center">
            <div class="form-group">
                <p class="text-info">
                    <strong>Output format:</strong>
                    <select name="outputFormat" class="form-control">
                        <option value="DOCX">DOCX</option>
                        <option value="PDF">PDF</option>
                    </select>
                </p>

            </div>
            <div class="col-md-12" align="center">
                <div class="form-group">
                    <button type="submit" class="form-control btn btn-success">Compare and Download</button>
                </div>
            </div>
        </div>
    </div>
</form>
<script> 
    // Drag and drop plugin options
    $("#input-id").fileinput({ 'showUpload': false, 'previewFileType': 'any', 'showClose': false });
    $("#input-id2").fileinput({ 'showUpload': false, 'previewFileType': 'any', 'showClose': false });
</script>