How to Programmatically Convert Word DOCX to PDF Using C# .NET

Download a 30-Day Free Trial of Document Solutions for Word Today!

Create a Sample C# .NET Core Console Application

Open Visual Studio 2022 and create a new C# Console App. We named ours DsWord_Convert_Word_to_PDFConsole.

Right-click the project in the Solution Explorer and choose Manage NuGet Packages. In the Package source at the top right, select nuget.org. Click the Browse tab on the top left and search for "DS.Documents." On the left panel, select DS.Documents.Word. In the Preview Changes dialog, click OK and choose I Accept on the next screen.

Add the needed namespaces to the Program.cs file:

using GrapeCity.Documents.Word;
using GrapeCity.Documents.Word.Layout;
using System.IO.Compression;

Load the Word Document (.docx) File into a C# .NET Word API

Now, we can load the Word DOCX file into a server-side Word instance.

Add the following lines of code in the main function of Program.cs to create a new DsWord document object, and then load the Word document into the object using the Load method.

// Initalize Word instance
var wordDoc = new GcWordDocument();
// Load DOCX file 
wordDoc.Load(@"ProcurementLetter.docx");

Save the .NET Word Instance as a PDF

To save the loaded DOCX file as a PDF, we need to get the layout of the .NET Word instance using the GcWordLayout class. The API allows us to define the options for saving the layout in PDF format using the PdfOutputSettings class setting. Options include:

• CompressionLevel: This specifies values that indicate whether a compression operation emphasizes speed or compression size. It requires the CompressionLevel Enum to set different values.
• PdfAConformanceLevel: It sets the PDF/A conformance levels with the help of the PdfAConformanceLevel Enum
• DocumentInfo: The DocumentInfo object contains information about the document, like author, title, creation date, etc.
• ImageOptions: It gets and sets the ImageOptions object, which contains options to control how images are processed in the current document.
• Linearized: It indicates whether the generated PDF should be saved as linearized.
• Metadata: It gets or sets the metadata associated with the document.
• PdfVersion: It gets or sets the PDF Version of the generated document.
  By default, the version is determined automatically based on which features are used in this document. Setting this property to a non-null string in the format "1.X" (where X is a digit from 0 to 9) overrides the automatic value with the specified one.
• BackColor: It sets the background color. The default is white.

Lastly, invoke the document layout’s SaveAsPdf method to save the loaded DOCX file as a PDF.

// Create an instance of the GcWordLayout
using (var layout = new GcWordLayout(wordDoc))
{
    // Define the PDF output settings
    PdfOutputSettings pdfOutputSettings = new PdfOutputSettings();
    pdfOutputSettings.CompressionLevel = CompressionLevel.Fastest;
    pdfOutputSettings.ConformanceLevel = GrapeCity.Documents.Pdf.PdfAConformanceLevel.PdfA1a;
    
    // Save the Word layout as a PDF
    layout.SaveAsPdf("ProcurementLetter.pdf", null, pdfOutputSettings);
}

Run the application and notice the PDF document will be generated in your project. And just like that, we have loaded the Word document and converted it to a PDF.

Ready to try the .NET Word API? Download a free trial today!

Learn More About This C# .NET Word API

This article only scratches the surface of the full capabilities of Document Solutions for Word, our .NET Word API library. Check out our online demo explorer and documentation to learn more.