GroupDocs.Annotation embeds collaborative annotation into your apps. Add, import, export, render, and manage comments, highlights, redactions, watermarks, and drawings across PDF, DOCX, PPTX, XLSX, images, CAD, and more—without external tools.

• Published GroupDocs.Annotation 25.12 release with importants fixes and (improvements)[https://releases.groupdocs.com/annotation/net/release-notes/2025/groupdocs-annotation-for-net-25-11-release-notes/].
• Refreshed samples.
• Check release notes for performance and rendering improvements across .NET and Java ports.

Server-side API to render, add, edit, remove, import, export, and search annotations in Office, PDF, images, and CAD.

• GroupDocs.Annotation-for-.NET: Core API with rendering, import/export, thumbnails, and cache support.
  Repo & examples: https://github.com/groupdocs-annotation/GroupDocs.Annotation-for-.NET
• Demos & UI samples: Showcase projects for web viewers and annotation workflows.
  Repo: https://github.com/groupdocs-annotation/GroupDocs.Annotation-for-.NET/tree/master/Demos

// Add annotations to a PDF and save only annotated pages
using (var annotator = new Annotator("input.pdf"))
{
    var area = new AreaAnnotation
    {
        Box = new Rectangle(100, 100, 140, 120),
        BackgroundColor = 65535,
        PageNumber = 1
    };

    var ellipse = new EllipseAnnotation
    {
        Box = new Rectangle(200, 140, 120, 120),
        BackgroundColor = 123456,
        PageNumber = 3
    };

    annotator.Add(new List<AnnotationBase> { area, ellipse });
    annotator.Save("result.pdf", new SaveOptions { OnlyAnnotatedPages = true });
}

Native Java library for adding, rendering, and exporting annotations across PDF, Office, images, and CAD.

• Repository: https://github.com/groupdocs-annotation/GroupDocs.Annotation-for-Java

// Quick Java example: add a highlight and save
try (Annotator annotator = new Annotator("contract.pdf")) {
    HighlightAnnotation highlight = new HighlightAnnotation();
    highlight.setPageNumber(1);
    highlight.setPoints(Arrays.asList(
        new Point(80, 120), new Point(220, 120),
        new Point(220, 150), new Point(80, 150)
    ));
    annotator.add(highlight);
    annotator.save("contract-annotated.pdf");
}

• Review and approval workflows with highlights, stamps, and threaded comments.
• Legal and compliance redaction of sensitive text and regions before sharing.
• Engineering and architecture markups on CAD drawings with shapes and measurements.
• Customer support and QA feedback directly on product docs, manuals, and images.
• Publishing workflows: watermarking drafts, exporting annotations, and creating thumbnails.

• 40+ formats: PDF, DOCX/DOC, XLSX/XLS, PPTX/PPT, VSDX/VSD, DWG/DXF, TIFF/JPG/PNG/BMP, HTML, MSG/EML, ODT/ODS/ODP, RTF, TXT, CSV, and more.
• Annotation objects: area, point, polyline, distance, ellipse, arrow, text field; highlight, underline, strikeout, replacement, link; diagonal/horizontal watermarks.
• Import/export: load existing annotations, export to original format, or serialize to XML/JSON.
• Rendering: view documents as images, generate thumbnails, and render specific pages or regions.
• Cache: built-in local cache plus custom providers (Amazon S3, Dropbox, etc.).
• Security & control: password-protected files, page-range processing, remove or update annotations programmatically.

• Office: DOC, DOCX, DOCM, DOT, DOTM, DOTX, RTF; XLS, XLSX, XLSM, XLSB; PPT, PPTX, PPS, PPSX; VSD, VSDX, VSS, VST
• Portable: PDF (including PDF/A profiles)
• Images: TIF, TIFF, JPG, JPEG, PNG, BMP
• CAD: DWG, DXF
• Email: EML, MSG
• Web & Other: HTML, ODT, ODS, ODP, DCM, TXT

• .NET: Install-Package GroupDocs.Annotation or dotnet add package GroupDocs.Annotation
• Java: Add groupdocs-annotation from Maven Central.
• Run sample projects in the repositories above to annotate PDFs, Office docs, images, or CAD files.

• Documentation and tutorials: https://docs.groupdocs.com/annotation/
• Free support forum: https://forum.groupdocs.com/c/annotation
• Temporary license for full-feature evaluation: https://purchase.groupdocs.com/temporary-license
• Product page and downloads: https://products.groupdocs.com/annotation

document-annotation pdf-annotation office-annotation cad-annotation image-annotation redaction watermarking commenting markup review-workflows collaborative-annotation document-viewer annotation-sdk dotnet-annotation java-annotation pdf-commenting docx-annotation ppt-annotation xls-annotation web-annotation render-annotations