What Are PDF Annotations?

PDF annotations are interactive elements that can be added to PDF documents to provide additional information, highlight important sections, add comments, or enable user interactivity. They allow users to collaborate on, mark up, and enhance the content of a PDF file. Annotations can be created, viewed, and manipulated using our PSPDFKit SDK tools.

PDF annotations can be used for various purposes, including reviewing and commenting on drafts, proofreading documents, collaborating on projects, providing feedback, adding visual cues, and enhancing the interactivity of a document. They offer a flexible and interactive way to engage with PDF content and facilitate communication and collaboration among users.

XMP annotations are XML-based objects specifically designed in our PSPDFKit SDKs to enrich and enhance the PDF annotation functionality.

Apart from the standard PDF annotation functionality, our dedicated AnnotationManager class enables you to add annotations not only to PDF documents, but also to images and TIFF files. The XMP annotations can also be saved to a separate XML file that’s independent from the source file. This makes it possible to apply different annotations to multiple files.


For a detailed description of how to use XMP annotations, refer to the XMP annotations guide.