PDF annotations allow "sticky note" like comments to be added to PDF pages. The IronPDF.PdfDocument.AddTextAnnotation method and PdfDocument.TextAnnotation class allows annotations to be added programmatically. Advanced text annotation features supported include coloring, sizing, opacity, icons, and editing.

How to Add PDF Annotation in .NET

  1. Install C# library to add annotation to PDF
  2. Open existing or generate new PDF in .NET
  3. Create TextAnnotation class and set customize properties
  4. Utilize AddTextAnnotation method to add the newly made annotation to PDF
  5. Export the modified PDF to desired folder