In this tutorial you’ll find stepwise instructions to compare PDF files using C#, plus guidance on configuring the document comparison library and a ready‑to‑run code snippet that demonstrates the C# compare PDF files capability. You can follow these steps without installing any third‑party software, and the solution works on any .NET‑compatible operating system, including Windows, Linux, and macOS.

Steps to Compare PDF Files using C#

1. Install GroupDocs.Comparison for .NET package from the NuGet website in the .NET project for comparing PDF files
2. Add a reference to the GroupDocs.Comparison namespace to compare two PDF documents
3. Instantiate Comparer class and pass the input PDF file to its constructor
4. Use Add method of the Comparer class for loading the target PDF document
5. Finally, invoke the Compare method to save the resultant PDF file to the disk

The compare two PDF files using C# functionality can be easily developed by following the above points in a sequence. In the first step, set up the required document comparison package and then reference the essential namespace. In the next step, load the source PDF file for comparison by creating an instance of the Comparer class and load the target PDF document by calling the Add method of the same class. In the last step, the resultant file can be saved to the disk by invoking the Compare method.

Code to Compare PDF Files using C#

In the code snippet above, we demonstrated the compare two PDF documents and highlight differences C# capability, leveraging just a few API calls from the document comparison library to build a PDF comparison tool. While this example works with two PDF files, you can easily extend the logic to compare multiple documents.

We’ve walked through the complete process for building PDF‑compare functionality in C#. If you’d like to explore document comparison further, see our recent guide on comparing Word files in C#: how to Compare Word documents using C#.