With this native .NET API, you can easily compare PDF documents and obtain the differences in the desired output format. Our C# library is fully self-contained and does not rely on any external tools or services. It eliminates the need for external dependencies, providing a comprehensive set of PDF processing functionalities within a single .NET package.

On this landing page, we bring you a live demo of the PDF comparison in action, coupled with an illustrative C# example. It compares the contents of PDF documents both at the character level and at the word level. Even if only a single character has been changed, the entire word will be marked as modified. Experience firsthand how easy it is to compare two documents by uploading PDF files to the interface, choosing the desired output format, and getting the differences between PDF documents marked with 100% accuracy.

Compare PDF using C#

Sometimes it may not be clear if a PDF file has been modified, and manually comparing two versions of a document can be a daunting task. Conversely, there are times when you're sure the PDF document has changed, but visually identifying the updated sections becomes overwhelming. The PDF comparison is an increasingly sought-after procedure, particularly within automated document workflows. Let's explore typical scenarios where automated PDF comparison can be highly valuable:

Version Control and Collaboration. When multiple contributors are working on the same PDF file, programmatic document comparison helps identify changes made by different individuals
Legal and Compliance. In the legal industry, accurate comparison of legal contracts, agreements, or regulatory documents is crucial. Automated PDF file comparison ensures precise detection of any modifications, additions, or omissions, helping legal professionals maintain compliance and mitigate legal risks
Quality Assurance and Testing. Software development often involves handling extensive documentation, such as requirements, specifications, and test cases. By automating PDF comparison, .NET developers can easily detect discrepancies between versions, ensuring consistency and accuracy throughout the development process
Content Management and Publishing. In content-driven industries, like publishing or journalism, maintaining consistency across different versions of articles, manuscripts, or books is essential. Comparing PDF documents programmatically allows authors and editors to quickly spot differences and ensure the integrity of their content, facilitating efficient publishing workflows

Find differences in PDF files in C#

As you can see, programmatic PDF comparison offers immense benefits in various domains, enabling streamlined workflows, enhanced collaboration, and increased productivity. With this C# API, you have the power to harness these advantages seamlessly within your .NET projects. Try out our live demo by uploading two PDF documents, selecting the target format to highlight the differences, and examining the C# code example. This C# snippet demonstrates how to find differences between PDF files and save the results in the required format.

An important point: the compared PDF documents should not have revisions before calling the comparison method. You must first accept all the revisions.

Compare two PDF files using C#

Input files

Upload the compared file

Run code

Upload the second file to compare

Output format

Select the target format from the list

dotnet add package Aspose.Words

Copy

using Aspose.Words;

var docA = new Document("Input1.pdf");
var docB = new Document("Input2.pdf");

// There should be no revisions before comparison.
docA.AcceptAllRevisions();
docB.AcceptAllRevisions();

docA.Compare(docB, "Author Name", DateTime.Now);
docA.Save("Output.pdf");

					Run code

You may freely download this code or copy it in any applicable purpose

How to compare two PDF in C#

Install Aspose.Words for .NET
Add a library reference (import the library) to your C# project
Load two PDF to compare
Accept all revisions before calling the Compare() method
Call the Compare() method to compare two PDF
Call the Save() method, passing an output filename with required extension
Get the result of compression PDF as a separate file

C# library to compare PDF documents

There are three alternative options to install "Aspose.Words for .NET" onto your system. Please choose one that resembles your needs and follow the step-by-step instructions:

Install a NuGet Package. See Documentation
Install the library using Package Manager Console within Visual Studio IDE
Install the library manually using Windows Installer

System Requirements

Our product is fully cross-platform and supports all major .NET implementations:

.NET ≥ 5.0
.NET Core ≥ 2.0
.NET Standard ≥ 2.0
.NET Framework ≥ 3.5
MonoMac
MonoAndroid
Xamarin

As far as .NET code doesn't depend on the underlying hardware or operating system, but only on a Virtual Machine, you are free to develop any kind of software for Windows, macOS, Android, iOS and Linux. Just make sure you have installed the corresponding version of .NET Framework, .NET Core, Windows Azure, Mono or Xamarin.

We recommend using Microsoft Visual Studio, Xamarin, and MonoDevelop integrated development environments to create C#, F#, VB.NET applications.

Fore more details please refer to Product Documentation.

You can perform compare operation for other file formats: