About Annotate PDF Online
Annotating PDFs directly in your browser eliminates the need for expensive desktop software. Add highlights, sticky notes, text comments, drawings, and stamps to any PDF. All annotations are saved within the PDF file and visible in any PDF reader.
Key Features
- Highlight, underline, and strikethrough text
- Sticky notes with threaded replies
- Freehand drawing and shape tools
- Text box insertion anywhere on page
- Stamp library (Approved, Draft, Confidential)
Common Use Cases
Ideal for document review workflows, academic paper markup, contract negotiation, proofreading, and collaborative editing where multiple reviewers need to add feedback.
Pro Tips
Use different highlight colors for different types of feedback (yellow for questions, green for approvals, red for issues). Export a summary of all annotations for quick review.
How to Use Annotate PDF Online
Step 1: Upload your file above.
Step 2: Configure options as needed.
Step 3: Click Process and download your result.
Why Choose PDF0.ai?
Unlike other tools that require subscriptions, Annotate PDF Online on PDF0.ai is completely free with unlimited usage.