PDF Redaction

Find and remove content in PDF documents with free cross-platform Apps and APIs

How to Redact PDF File

In order to redact PDF file, we’ll use Aspose.PDF API which is a feature-rich, powerful and easy to use document manipulation API for any platform. Open NuGet package manager, search for Aspose.PDF and install. You may also use the following command from the Package Manager Console.

Redact PDF documents


You need Aspose.PDF library to try the code in your environment.

  1. Load the PDF with an instance of Document.
  2. Create TextFragmentAbsorber object with search terms as argument.
  3. Set Search Options.
  4. Loop through each fragment collect to redact.
  5. Save PDF file.

System Requirements


Just make sure that you have the following prerequisites.

  • Microsoft Windows or a compatible OS with .NET Framework, .NET Core, and PHP, VBScript, C++ via COM Interop.
  • Development environment like Microsoft Visual Studio.
  • Aspose.PDF for .NET DLL referenced in your project.

Redact PDF - C#.


    Document doc = new Document(dataDir + "test.pdf");

    TextFragmentAbsorber textFragmentAbsorber = new TextFragmentAbsorber(searchTerm);
    TextSearchOptions textSearchOptions = new TextSearchOptions(true);
    textFragmentAbsorber.TextSearchOptions = textSearchOptions;

    doc.Pages.Accept(textFragmentAbsorber);
    TextFragmentCollection textFragmentCollection = textFragmentAbsorber.TextFragments;
    foreach (TextFragment textFragment in textFragmentCollection)
{
    Page page = textFragment.Page;
    Rectangle annotationRectangle = textFragment.Rectangle;

    Annotations.RedactionAnnotation annot = new Annotations.RedactionAnnotation(page, annotationRectangle);
    annot.FillColor = Color.Black;
    doc.Pages[textFragment.Page.Number].Annotations.Add(annot, true);
    annot.Redact();
}
    doc.Save(dataDir + "output.pdf");

About Aspose.PDF API

Aspose.PDF API can be used for PDF document manipulation and parsing within applications. One can create, modify, compress, secure, print or save PDF to TXT, HTML, PCL, XFA, XML, XPS, EPUB, TEX, Images and more formats. Aspose.PDF is a standalone API and it does not depend on any software including Adobe Acrobat.