How to Convert Word (Docx) to PDF in C# (Tutorial)

Benefits of PDF Over DOCX

PDF is the gold standard for sharing and archiving documents due to its:

• Platform Independence: PDFs look the same regardless of the operating system or device used to open them.

• Data Integrity: Text, images, fonts, and layouts are preserved exactly as intended.

• Security: PDFs support encryption, password protection, and digital signatures, ensuring document confidentiality and authenticity.

Common Scenarios for Word-to-PDF Conversion

Here are some real-world scenarios where Word-to-PDF conversion is essential:

• Contracts and Legal Documents: Generate contracts that preserve formatting and cannot be easily edited.

• Business Reports: Share polished, professional reports with consistent formatting.

• Invoice Generation: Automate invoice creation in a tamper-proof format.

• Document Archiving: Save important Word documents in a long-term, unmodifiable format.

Step 1: Installing IronPDF

IronPDF is available via NuGet. Open your Package Manager Console and run:

Install-Package IronPdf

Alternatively, you can install it via the NuGet Package Manager in Visual Studio. Just go to tools > NuGet Package Manager > Manage NuGet Packages for Solution:

And then search for IronPDF. Here you can install the IronPDF library to your project.

Step 2: Activating Your License

IronPDF offers a free trial, but you’ll need to activate a license key for full functionality. To activate, simply add your license key in your code:

IronPdf.License.LicenseKey = "YOUR_LICENSE_KEY_HERE";

IronPdf.License.LicenseKey = "YOUR_LICENSE_KEY_HERE";

Input Word Document

Basic Example Code

The below sample code demonstrates the straightforward process to convert DOCX files to PDF.

using IronPdf;  
using System.IO;  

class Program  
{  
    static void Main(string[] args)  
    {  
        // Create a new DocxToPdfRenderer object
        DocxToPdfRenderer renderer = new DocxToPdfRenderer();

        // Convert DOCX to PDF using IronPDF  
        PdfDocument pdf = renderer.RenderDocxAsPdf("newsletter.docx");

        // Save the resulting PDF to a file  
        pdf.SaveAs("output.pdf"); 
    }  
}

using IronPdf;  
using System.IO;  

class Program  
{  
    static void Main(string[] args)  
    {  
        // Create a new DocxToPdfRenderer object
        DocxToPdfRenderer renderer = new DocxToPdfRenderer();

        // Convert DOCX to PDF using IronPDF  
        PdfDocument pdf = renderer.RenderDocxAsPdf("newsletter.docx");

        // Save the resulting PDF to a file  
        pdf.SaveAs("output.pdf"); 
    }  
}

Output PDF Document

1. Adding Watermarks

Watermarks are useful for branding or marking sensitive documents. You can add watermarks after converting the PDF:

pdf.ApplyWatermark("<h2 style='color:red'>SAMPLE Copy</h2>", 40, IronPdf.Editing.VerticalAlignment.Middle, IronPdf.Editing.HorizontalAlignment.Center);

pdf.ApplyWatermark("<h2 style='color:red'>SAMPLE Copy</h2>", 40, IronPdf.Editing.VerticalAlignment.Middle, IronPdf.Editing.HorizontalAlignment.Center);

2. Adding Headers to Your PDF

One of the most common customizations for PDFs is adding headers to each page. Headers can include document titles, page numbers, dates, or any other information you wish to display at the top of each page in the PDF.

TextHeaderFooter textHeader = new TextHeaderFooter
{
    CenterText = "Weekly Newsletter!",
};

pdf.AddTextHeaders(textHeader);

TextHeaderFooter textHeader = new TextHeaderFooter
{
    CenterText = "Weekly Newsletter!",
};

pdf.AddTextHeaders(textHeader);

3. Customizing PDF Layout

IronPDF allows you to define page settings, such as margins, orientation, and page size, before saving your PDF:

renderer.RenderingOptions.PaperOrientation = PdfPaperOrientation.Portrait;

renderer.RenderingOptions.SetCustomPaperSizeinCentimeters(20, 20);

renderer.RenderingOptions.MarginTop = 30;
renderer.RenderingOptions.MarginLeft = 20;
renderer.RenderingOptions.MarginRight = 20;
renderer.RenderingOptions.MarginBottom = 30;

renderer.RenderingOptions.PaperOrientation = PdfPaperOrientation.Portrait;

renderer.RenderingOptions.SetCustomPaperSizeinCentimeters(20, 20);

renderer.RenderingOptions.MarginTop = 30;
renderer.RenderingOptions.MarginLeft = 20;
renderer.RenderingOptions.MarginRight = 20;
renderer.RenderingOptions.MarginBottom = 30;

Full Example Code with Extra Formatting

using IronPdf;
using IronPdf.Rendering;

public class Program
{
    public static void Main(string[] args)
    {
        // Create a new DocxToPdfRenderer object
        DocxToPdfRenderer renderer = new DocxToPdfRenderer();

        // Set paper orientation and custom size for the PDF
        renderer.RenderingOptions.PaperOrientation = PdfPaperOrientation.Portrait;
        renderer.RenderingOptions.SetCustomPaperSizeinCentimeters(15, 15);

        // Set margins for the PDF document
        renderer.RenderingOptions.MarginTop = 15;
        renderer.RenderingOptions.MarginLeft = 20;
        renderer.RenderingOptions.MarginRight = 20;
        renderer.RenderingOptions.MarginBottom = 15;

        // Convert DOCX to PDF using IronPDF  
        PdfDocument pdf = renderer.RenderDocxAsPdf("newsletter.docx");

        // Apply a watermark to the PDF document
        pdf.ApplyWatermark("<h2 style='color:red'>SAMPLE Copy</h2>", 40, IronPdf.Editing.VerticalAlignment.Middle, IronPdf.Editing.HorizontalAlignment.Center);

        // Add text headers to the PDF document
        TextHeaderFooter textHeader = new TextHeaderFooter
        {
            CenterText = "Weekly Newsletter!",
        };

        pdf.AddTextHeaders(textHeader);

        // Save the resulting PDF to a file  
        pdf.SaveAs("output.pdf");
    }
}

using IronPdf;
using IronPdf.Rendering;

public class Program
{
    public static void Main(string[] args)
    {
        // Create a new DocxToPdfRenderer object
        DocxToPdfRenderer renderer = new DocxToPdfRenderer();

        // Set paper orientation and custom size for the PDF
        renderer.RenderingOptions.PaperOrientation = PdfPaperOrientation.Portrait;
        renderer.RenderingOptions.SetCustomPaperSizeinCentimeters(15, 15);

        // Set margins for the PDF document
        renderer.RenderingOptions.MarginTop = 15;
        renderer.RenderingOptions.MarginLeft = 20;
        renderer.RenderingOptions.MarginRight = 20;
        renderer.RenderingOptions.MarginBottom = 15;

        // Convert DOCX to PDF using IronPDF  
        PdfDocument pdf = renderer.RenderDocxAsPdf("newsletter.docx");

        // Apply a watermark to the PDF document
        pdf.ApplyWatermark("<h2 style='color:red'>SAMPLE Copy</h2>", 40, IronPdf.Editing.VerticalAlignment.Middle, IronPdf.Editing.HorizontalAlignment.Center);

        // Add text headers to the PDF document
        TextHeaderFooter textHeader = new TextHeaderFooter
        {
            CenterText = "Weekly Newsletter!",
        };

        pdf.AddTextHeaders(textHeader);

        // Save the resulting PDF to a file  
        pdf.SaveAs("output.pdf");
    }
}

With this, you can easily convert your DOCX files to a PDF file with custom formatting to fit your needs.

Output PDF Document

1. Optimize File Sizes

Reduce PDF size by compressing any images within your PDF for faster downloads and smoother sharing:

pdf.CompressImages(40);

pdf.CompressImages(40);

2. Validate Input Files

Always ensure the DOCX file exists and is valid before processing:

if (!File.Exists(docxPath))  
{  
    throw new FileNotFoundException($"File not found: {docxPath}");  
}

if (!File.Exists(docxPath))  
{  
    throw new FileNotFoundException($"File not found: {docxPath}");  
}

3. Secure Your PDFs

Encrypt sensitive documents with a password:

pdf.SecuritySettings.OwnerPassword = "SecurePassword123";
pdf.SecuritySettings.UserPassword = "Password";

pdf.SecuritySettings.OwnerPassword = "SecurePassword123";
pdf.SecuritySettings.UserPassword = "Password";

Key Features of IronPDF

1. HTML to PDF Conversion:

   • One of the most powerful features of IronPDF is its ability to convert HTML content into PDFs. This makes it perfect for web applications where users need to download reports, invoices, or other documents in PDF format.

   • It supports advanced HTML and CSS, including JavaScript execution, which ensures that the PDF output closely matches the web page design.

2. Image to PDF Conversion:

   • IronPDF can also take images (JPEG, PNG, etc.) and convert them into high-quality PDFs, which is ideal for creating portfolios, photo books, and scanned document archives. Alternatively, IronPDF also supports PDF to image conversion.

3. PDF Editing:

   • You can edit existing PDFs by adding text, images, shapes, annotations, or watermarks. The library also supports merging and splitting PDF files, making it a great tool for document management applications.

4. Form Filling and PDF Generation:

   • IronPDF allows developers to fill form fields in existing PDFs, making it perfect for applications where users need to fill out interactive forms and save them as PDFs.

5. Text Extraction:

   • IronPDF can extract text from PDFs, which can then be used for data analysis, searching, or exporting to other formats (like CSV or Excel). It’s ideal for document processing workflows that need to analyze the content of PDFs.