How to Add and Edit PDF Annotations
Annotations allow users to add comments, reminders, or additional information to specific sections of the document. They enhance collaboration and communication in working with PDFs, enabling users to annotate, comment on, and provide context for shared content.
How to Add and Edit PDF Annotations
- Download the C# library to add, edit, and remove PDF annotations
- Load an existing or render a new PDF document
- Use the
Addmethod to add annotations to the PDF file - Retrieve and edit the annotation collection of the PDF
- Remove a single annotation or all annotations on a particular page or the entire document
Install with NuGet
Install-Package IronPdf
Install with NuGet
Install-Package IronPdf
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Add Annotations Example
PDF annotations allow the addition of "sticky note"-like comments to PDF pages. By using the Add method of the Annotations property, annotations can be programmatically added.
Tips
:path=/static-assets/pdf/content-code-examples/how-to/annotation-add-annotation.csusing IronPdf;
using IronPdf.Annotations;
ChromePdfRenderer renderer = new ChromePdfRenderer();
PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Annotation</h1>");
// Create a PDF annotation object on a specified page index
TextAnnotation annotation = new TextAnnotation(0)
{
Title = "This is the title",
Contents = "This is the long 'sticky note' comment content...",
X = 50,
Y = 700,
};
// Add the annotation
pdf.Annotations.Add(annotation);
pdf.SaveAs("annotation.pdf");IRON VB CONVERTER ERROR developers@ironsoftware.comPDF with an Annotation
The annotation in the PDF document above can be viewed with the Chrome browser.
Retrieve and Edit Annotations Example
Retrieving and editing PDF annotations improves collaboration by enhancing clarity, accuracy, and usability. Access the annotation collection through the Annotations property and update properties such as Title, Contents, X, Y, and more with new information.
:path=/static-assets/pdf/content-code-examples/how-to/annotation-edit-annotation.csusing IronPdf;
using IronPdf.Annotations;
using System.Linq;
PdfDocument pdf = PdfDocument.FromFile("annotation.pdf");
// Retrieve annotation collection
PdfAnnotationCollection annotationCollection = pdf.Annotations;
// Select the first annotation
TextAnnotation annotation = (TextAnnotation)annotationCollection.First();
// Edit annotation
annotation.Title = "New title";
annotation.Contents = "New content...";
annotation.X = 150;
annotation.Y = 800;
pdf.SaveAs("editedAnnotation.pdf");Imports IronPdf
Imports IronPdf.Annotations
Imports System.Linq
Private pdf As PdfDocument = PdfDocument.FromFile("annotation.pdf")
' Retrieve annotation collection
Private annotationCollection As PdfAnnotationCollection = pdf.Annotations
' Select the first annotation
Private annotation As TextAnnotation = CType(annotationCollection.First(), TextAnnotation)
' Edit annotation
annotation.Title = "New title"
annotation.Contents = "New content..."
annotation.X = 150
annotation.Y = 800
pdf.SaveAs("editedAnnotation.pdf")PDF with an Edited Annotation
The annotation in the PDF document above can be viewed with the Chrome browser.
Remove Annotation Example
Easily remove unnecessary or outdated annotations using the following methods: RemoveAt, RemoveAllAnnotationsForPage, and Clear.
- RemoveAt: Remove a single annotation with a specified index.
- RemoveAllAnnotationsForPage: Remove all annotations on a specified page.
- Clear: Remove all annotations in the document.
Remove a Single Annotation
To remove a single annotation, use the RemoveAt method with the corresponding index based on the annotation collection index.
:path=/static-assets/pdf/content-code-examples/how-to/annotation-remove-single-annotation.csusing IronPdf;
PdfDocument pdf = PdfDocument.FromFile("multipleAnnotation.pdf");
// Remove a single annotation with specified index
pdf.Annotations.RemoveAt(1);
pdf.SaveAs("removeSingleAnnotation.pdf");Imports IronPdf
Private pdf As PdfDocument = PdfDocument.FromFile("multipleAnnotation.pdf")
' Remove a single annotation with specified index
pdf.Annotations.RemoveAt(1)
pdf.SaveAs("removeSingleAnnotation.pdf")Removed a Single Annotation on PDF
Before
After
The annotation in the PDF document above can be viewed with the Chrome browser.
Remove All Annotations
To remove all annotations on a particular page, use the RemoveAllAnnotationsForPage method and specify the page index. If you want to remove all annotations in the entire document, simply call the Clear method on the Annotations property.
:path=/static-assets/pdf/content-code-examples/how-to/annotation-remove-all-annotation.csusing IronPdf;
PdfDocument pdf = PdfDocument.FromFile("multipleAnnotation.pdf");
// Remove all annotaions on a specified page
pdf.Annotations.RemoveAllAnnotationsForPage(0);
// Remove all annotaions on the document
pdf.Annotations.Clear();
pdf.SaveAs("removeAllAnnotation.pdf");Imports IronPdf
Private pdf As PdfDocument = PdfDocument.FromFile("multipleAnnotation.pdf")
' Remove all annotaions on a specified page
pdf.Annotations.RemoveAllAnnotationsForPage(0)
' Remove all annotaions on the document
pdf.Annotations.Clear()
pdf.SaveAs("removeAllAnnotation.pdf")
