GroupDocs.Annotation for Python via .NET Overview

What is GroupDocs.Annotation?

GroupDocs.Annotation for Python via .NET is a native Python library that adds, edits, and removes annotations and markup on documents — across PDF, Microsoft Word, Excel, PowerPoint, images, CAD, Visio, and email formats — through a single, format-independent API. It runs entirely on-premise, requires no Microsoft Office or Adobe Acrobat installation, and ships as a pre-built wheel on Windows, Linux, and macOS.

Typical uses include:

  • Document review & collaboration — add area, shape, and text-markup annotations and attach threaded reviewer comments so teams can discuss a document in place.
  • Legal & contract markup — highlight clauses, strike out obsolete text, and flag regions that need attention before a document is signed or shared.
  • Engineering & design review — annotate CAD drawings and Visio diagrams with area, arrow, and distance markups.
  • Content & e-learning feedback — mark up images and scanned pages with points, watermarks, and image stamps.
  • Automated annotation pipelines — stamp watermarks, links, and notes across many documents and save only the annotation types or page ranges you need.

Key Capabilities

Capability Description
Shape Annotations Draw area, ellipse, arrow, point, distance, and polyline annotations with configurable color and opacity.
Text Markup Highlight, underline, strikeout, and squiggly-mark text, plus replacement, text-redaction, and resources-redaction annotations.
Content Annotations Stamp watermarks, image annotations, hyperlinks, and editable text fields onto a document.
Comments & Replies Attach threaded review comments — with user and timestamp — to any annotation.
Manage Annotations List, update, and remove annotations, all of them or filtered by annotation type.
Save Filters Render only selected annotation types, or a specific page range, when saving the result.
Document Inspection Read file type, page count, and size without modifying the document.

Every capability is covered with runnable, copy-paste examples in the Developer Guide.

Quick Example

Add an annotation and save the result with just a few lines of code. The example draws a yellow area annotation on the first page of sample.pdf and writes the result to annotated.pdf:

from groupdocs.annotation import Annotator
from groupdocs.annotation.models import Rectangle
from groupdocs.annotation.models.annotation_models import AreaAnnotation
from groupdocs.pydrawing import Color

def annotate_area():
    # Open the document
    with Annotator("./sample.pdf") as annotator:
        # Build an area annotation on the first page
        area = AreaAnnotation()
        area.box = Rectangle(100, 100, 200, 80)        # x, y, width, height
        area.page_number = 0                            # 0-based page index
        area.background_color = Color.yellow.to_argb()  # ARGB int, not a Color object
        area.message = "Review this section"
        annotator.add(area)
        # Save the annotated document
        annotator.save("./annotated.pdf")

if __name__ == "__main__":
    annotate_area()

sample.pdf is the sample file used in this example. Click here to download it.

Binary file (PDF, 1.0 MB)

Download full output

For richer review workflows, add several annotations, attach a comment thread, and save only the area annotations with a page-range filter using SaveOptions:

from groupdocs.annotation import Annotator
from groupdocs.annotation.models import Rectangle, Point, Reply
from groupdocs.annotation.models.annotation_models import AreaAnnotation, HighlightAnnotation
from groupdocs.annotation.options import SaveOptions, AnnotationType
from groupdocs.pydrawing import Color

def annotate_with_options():
    with Annotator("./sample.pdf") as annotator:
        # An area annotation carrying a threaded review comment
        area = AreaAnnotation()
        area.box = Rectangle(100, 100, 200, 80)
        area.page_number = 0
        area.background_color = Color.yellow.to_argb()
        area.message = "Please review"
        reply = Reply()
        reply.comment = "Confirmed, looks good"
        area.replies = [reply]

        # A text highlight described by a quad of points
        highlight = HighlightAnnotation()
        highlight.page_number = 0
        highlight.font_color = Color.lime.to_argb()
        highlight.points = [Point(80, 730), Point(240, 730), Point(240, 750), Point(80, 750)]

        annotator.add([area, highlight])

        # Render only area annotations, and only the first page
        options = SaveOptions()
        options.annotation_types = AnnotationType.AREA
        options.first_page = 1      # SaveOptions pages are 1-based
        options.last_page = 1
        annotator.save("./annotated.pdf", save_options=options)

if __name__ == "__main__":
    annotate_with_options()

sample.pdf is the sample file used in this example. Click here to download it.

Binary file (PDF, 1.0 MB)

Download full output

Where to next

  1. Install the package — Installation walks through PyPI and offline wheel installation for Windows, Linux, and macOS.
  2. Run your first annotation — Hello, World! annotates a document in under five minutes.
  3. Explore runnable examples — How to Run Examples clones the GitHub repository and runs every documented scenario locally or in Docker.
  4. Use it in depth — the Developer Guide covers every API surface with runnable, copy-paste code examples.
  5. Plug it into AI pipelines — AI Agents & LLM Integration explains the bundled AGENTS.md, the MCP server, and machine-readable docs.
Features Overview Install GroupDocs.Annotation for Python via .NET