⚡ 100% Local • No Upload • Free Forever

PDF Annotator Tool – Annotate PDF Online

Upload a PDF and add annotations: highlights, sticky notes, freehand drawings, rectangles, and lines. All processing is done locally in your browser — your files never leave your device.

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Upload a PDF to annotate

Click or drag & drop — max 50 MB per file.

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No annotations yet. Use the tools above to add annotations.

💡 Pro tip: Use the highlight tool to mark important text, add sticky notes for comments, draw freehand with the pen, or add shapes. All annotations are saved per page and exported with your PDF.

Complete Guide: Annotate PDF Online Free

Our PDF Annotator Tool lets you add annotations to PDF documents directly in your browser. Whether you're reviewing documents, studying, or collaborating, this tool makes it easy to highlight text, add notes, draw shapes, and more. No upload to servers — your data stays private.

1. Why Annotate PDFs?

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Study & review

Highlight key information and add notes while studying.

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Collaborate

Share annotated PDFs with colleagues for feedback.

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Review documents

Mark up contracts, reports, and legal documents.

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100% private

All processing is done locally — your files never leave your device.

2. How to Use the PDF Annotator Tool

Upload your PDF — Click the upload area or drag & drop a PDF file (max 50 MB).
Select an annotation tool — Choose from highlight, note, pen, rectangle, or line.
Annotate on the page — Click, drag, or draw on the page to add annotations.
Navigate pages — Use the previous/next buttons to move between pages.
Download — Click "Download Annotated PDF" to save your work.

All annotations are saved locally in your browser session. Your files are never transmitted to any server.

3. Annotation Tools Overview

🖍️ Highlight — Mark text with a semi-transparent color

📝 Note — Add a sticky note with custom text

✏️ Pen — Freehand drawing with variable size

⬜ Rectangle — Draw rectangles around content

📏 Line — Draw straight lines

4. Frequently Asked Questions

We support PDF files for annotation. The tool works with standard PDF documents including scanned pages, text-based PDFs, and forms.

Absolutely not! All processing is done locally in your browser using PDF.js and pdf-lib. Your files never leave your device.

You can add highlights, sticky notes, freehand drawings (pen), rectangles, and lines. Each annotation can be customized with different colors and sizes.

Unlimited! Use it as many times as you need, completely free.

📝 Final Verdict: The Best Free PDF Annotator Tool

Whether you're studying, reviewing documents, or collaborating with colleagues, our PDF Annotator Tool offers speed, privacy, and a full suite of annotation tools. No installation, no subscription, and most importantly: your data never leaves your device. Start annotating today.