Annotations Your business is spending too much on yearly subscriptions for PDF security and compliance. Consider IronSecureDoc, which provides solutions for managing SaaS services like digital signing, redaction, encryption, and protection, all for one-time payment. Explore IronSecureDoc Documentation PDF annotations allow "sticky note"-like comments to be added to PDF pages. The IronPDF.PdfDocument.AddTextAnnotation method and PdfDocument.TextAnnotation class allow annotations to be added programmatically. Advanced text annotation features supported include coloring, sizing, opacity, icons, and editing. How to Add PDF Annotation in .NET Install C# library to add annotation to PDF. Open an existing or generate a new PDF in .NET. Create a TextAnnotation class and customize properties. Utilize the AddTextAnnotation method to add the newly created annotation to the PDF. Export the modified PDF to the desired folder. Explore How to Add Annotations to PDFs with IronPDF View on GitHub Code https://github.com/irondarrius/IronPdf.Examples/tree/main/examples/annotations Download ZIP Related Tutorial Related How-To Guide Class Documentation Get Language Packs Download IronPDF DLL Report an Issue on this page Ready to Get Started? Nuget Downloads 16,383,823 | Version: 2025.11 just released Free NuGet Download Total downloads: 16,383,823 View Licenses
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