The GroupDocs.Annotation Cloud is a REST API and universal document annotator that supports almost all common business document and image file formats. It gives developers an API for creating advanced online document annotation tools. With GroupDocs.Annotation Cloud API developers can deliver advanced annotation features to their users quickly. It provides features for export/import annotations into/from files, additionally to possibility to save files in supported formats.


GroupDocs.Annotation Cloud REST API supports following type of Annotations:

Area – add notes to an area highlighted with a rectangle.
Arrow – The annotation type that draws an arrow on the document page.
Distance – measure the distance between any objects in a document.
Ellipse – The annotation of elliptic form that marks parts of document content.
Link – The annotation type that represents a hyperlink to a remote resource.
Point – add notes to any point in the document.
Polyline – draw freehand lines and shapes.
ResourcesRedaction – The annotation type that hides textual content behind black rectangle.
TextField – The text field annotation type represents textual comment inside colored frame.
TextHighlight – The annotation type that highlights and comments selected text.
TextRedaction – The annotation type that fills part of selected text with black rectangle.
TextReplacement – The annotation type that replaces original text with other provided text fragment.
TextStrikeout – The annotation type that marks text fragment with a strike through styling.
TextUnderline – The annotation type that marks text with a underline styling.
Watermark – The annotation type that adds textual watermark over document page.
Image – The annotation type that adds image overlay over document page content.

Supported Formats

DOCMicrosoft Word 97-2003 Document
DOCMMicrosoft Word Macro-Enabled Document
DOCXMicrosoft Word Document
DOTMicrosoft Word 97-2003 Template
DOTMMicrosoft Word Macro-Enabled Template
DOTXMicrosoft Word Template
RTFRich Text Document
ODTOpenDocument Text
XLSMicrosoft Excel 97-2003 Worksheet
XLSBMicrosoft Excel Binary Worksheet
XLSMMicrosoft Excel Macro-Enabled Worksheet
XLSXMicrosoft Excel Worksheet
ODSOpenDocument Spreadsheet
PPTMicrosoft PowerPoint 97-2003 Presentation
PPTXMicrosoft PowerPoint Presentation
PPSXMicrosoft PowerPoint Slide Show
ODPOpenDocument Presentation
PPSMicrosoft PowerPoint 97-2003 Slide Show
TIF, TIFFTagged Image File Format (TIFF)
JPG, JPEGJoint Photographic Experts Group (JPEG)
PNGPortable Network Graphics (PNG)
BMPBitmap Picture (BMP)
PDFAdobe Portable Document Format (PDF)
HTMLHyperText Markup Language (HTML)
EMLE-mail Message
VSDMicrosoft Visio 2003-2010 Drawing
VSDXMicrosoft Visio Drawing
VSSMicrosoft Visio 2003-2010 Stencil
VSTMicrosoft Visio 2013 Stencil
DWGAutodesk Design Data Formats
DXFDrawing Interchange Format
DCMDigital Imaging and Communications in Medicine (DICOM)

Security and Authentication

The GroupDocs.Annotation Cloud API is secured and requires authentication. Developers can generate a new application with an unique Client Id and Client Secret combination after registering to our dashboard. Authenticated requests require a Bearer authorization header with a JWT Token obtained by using the previously specified Cliend Id + Client Secret credentials. You can check complete details about authenticating your calls to our API here.

SDK examples

GroupDocs.Annotation Cloud comes with SDKs for different platforms to use this REST API in your specific project effortlessly. Checkout our GitHub repository for a complete list of GroupDocs.Annotation SDKs along with working examples, to get you started in no time.

API Explorer

The easiest way to try out our API right away in your browser! With the GroupDocs.Cloud Web API Explorer.
This is a collection of Swagger documentation for the GroupDocs.Cloud APIs. You can get information about all the resources in the API. It also provides testing and interactivity to our API endpoint documentation.