About Syncfusion Annotation in Blazor PDF Viewer Component

14 Aug 20261 minute to read

Annotations in the SfPdfViewer are interactive elements that allow users to add notes, highlights, or text boxes directly to a PDF document. They add context and feedback to PDFs, simplifying collaboration during document reviews.

The Blazor SfPdfViewer provides a complete set of annotation tools for reviewing, measuring, and marking up PDFs.

Supported annotations

Annotation manipulation capabilities

  • Create annotations: Use the toolbar, context menu, or APIs to add highlights, notes, shapes, and more directly onto the PDF document.
  • Edit annotations: Modify existing annotations by moving, resizing, or updating text and style properties like color, opacity, and thickness.
  • Delete annotations: Remove unwanted annotations using the context menu or the DeleteAnnotationAsync API.
  • Customize annotations: Adjust appearance and behavior—such as fonts, fill colors, and opacity—through the UI or configuration options.
  • Undo and redo annotations: Revert or reapply annotation actions (add, edit, delete) using toolbar buttons or corresponding APIs.
  • Import and export annotations: Save and load annotations in JSON (.json) or XFDF (.xfdf) formats to persist markups across sessions or share them with others.
  • Set permissions: Enable or disable the AnnotationPermission enum value (default: AnnotationPermission.All) to control which annotation actions users can perform.
  • Add and manage comments: Insert, edit, and delete comments or sticky notes attached to annotations for clearer feedback and collaboration. The Comments pane must be enabled in the toolbar settings.

See also