How to Add Comments and Notes to PDF
Add comments to PDF files, without losing quality or formatting. Insert sticky notes, text annotations, and threaded comment discussions.
What This Annotation Guide Covers
This guide was written and tested by Priya Nair, a Academic Publishing Coordinator with 5 years of hands-on experience in academic publishing, thesis formatting, citation management. Priya managed the PDF workflow for a university press for 5 years, handling everything from manuscript submission to final print-ready files.
Comments and notes attached to specific locations in a PDF are the backbone of document review workflows. A reviewer flags a clause in a contract with 'Please verify this date', an editor suggests 'Consider rephrasing for clarity' next to a paragraph, or a teacher writes 'Good argument' in a student's paper margin. Unlike email feedback, PDF comments are anchored to the exact location they reference.
This guide covers four methods for adding comments and notes to PDFs. We tested each on contract review, academic grading, and editorial workflows to evaluate comment positioning, formatting, and management capabilities.
Time to read: 3-4 minutes | Difficulty: Beginner | Last updated: 2026-07-25
Related Annotation Guides
While reading this page, these related guides may save you time:
Marking Up the PDF Step by Step with a Desktop Editor
1 Open the PDF and Switch to Comment Mode
Launch your desktop PDF editor and open the document. Switch to Comment or Annotate mode. The comment tools appear in the toolbar: Sticky Note, Text Box, Callout, and Stamp. The comments panel opens on the right side, showing existing comments (if any).
2 Add a Comment at the Desired Location
Select the Sticky Note tool and click on the page where you want to place the comment. A sticky note icon appears at the click location, and a comment dialog opens. Type your comment text. Use rich text formatting (bold, italic, lists) if needed. The comment is attributed to your username and timestamped.
3 Manage Comments in the Comments Panel
The comments panel lists all comments in the document, sorted by page number. Click a comment to jump to its location on the page. Filter by author, status, or color. Search for specific text within comments. Reply to comments to create threaded discussions. Set status (open, resolved, rejected) for review tracking.
4 Reply to and Resolve Comments
For collaborative review, reply to other reviewers' comments by selecting them and clicking Reply. To resolve a comment after addressing the feedback, right-click and set status to Resolved. Resolved comments can be hidden via filter to focus on remaining open items.
5 Save and Export Comment Summary
Save the file with comments embedded. If your editor supports it, export a comment summary report (PDF or text) listing all comments with page references, authors, and statuses. Open the file in a different reader to verify comments display correctly and are attributed properly.
📋 Quick Recap of the Annotation Steps
Print this box or keep it open while you work through the tutorial.
- 1Launch your desktop PDF editor and open the document. Switch to Comment or Annotate mode. The comment tools appear in the toolbar:…
- 2Select the Sticky Note tool and click on the page where you want to place the comment. A sticky note icon appears at the click loc…
- 3The comments panel lists all comments in the document, sorted by page number. Click a comment to jump to its location on the page.…
- 4For collaborative review, reply to other reviewers' comments by selecting them and clicking Reply. To resolve a comment after addr…
- 5Save the file with comments embedded. If your editor supports it, export a comment summary report (PDF or text) listing all commen…
Free Ways to Annotate a PDF (and Their Limits)
No desktop editor installed? Here are free alternatives — we list their limitations honestly.
Method 1: Microsoft Edge (Windows)
Add text comments via the Add Text tool. Comments are positioned freely on the page. Limitation: no sticky note markers; no threading; no status tracking; plain text only.
Method 2: Preview (macOS)
Add text boxes and speech bubble shapes as comments. Limitation: no comment threading; no status tracking; no export; limited formatting.
Method 3: Adobe Acrobat Reader (Free)
Full sticky note comments with author attribution and timestamps. Comments can be sorted and searched. Limitation: no comment export in free version; no rich text formatting; threading is basic.
Annotation Tools Compared: Free vs. Desktop
We tested each method on real documents to give you an honest comparison.
| Method | Annotate | Precision | Offline | Free |
|---|---|---|---|---|
| Microsoft Edge | Basic | ★★ | ✔ | ✔ |
| macOS Preview | Basic | ★★★ | ✔ | ✔ |
| Adobe Acrobat Reader | Full | ★★★★ | ✔ | ✔ |
| LibreOffice Draw | Full | ★★★ | ✔ | ✔ |
| Desktop Editor | Full | ★★★★★ | ✔ | Trial |
Verdict: Edge and Preview cover basic highlighting. For stamps, measurements, and professional markup, a desktop editor is the clear choice.
Annotating PDFs: Common Questions, Answered
How do I reply to a comment left by another reviewer?
In a desktop editor's comment panel, select the comment you want to reply to. Click 'Reply' and type your response. The reply appears indented under the original comment, creating a threaded discussion. Each reply is attributed to its author and timestamped. This is useful for resolving disagreements or asking clarifying questions about specific feedback.
Can I export all comments as a summary report?
Yes. Desktop editors can generate a comment summary — a new PDF or text document listing all comments with their page numbers, author names, timestamps, and comment text. This is useful for review meetings where stakeholders discuss feedback without opening the PDF. Some editors also export comments as CSV for import into tracking systems.
How do I mark comments as resolved after addressing the feedback?
Select the comment in the comment panel, right-click, and choose 'Set Status → Resolved' (or 'Accepted', 'Rejected', 'Cancelled' as appropriate). The comment marker changes appearance (typically becomes lighter or shows a checkmark) to indicate it has been addressed. Filter the comment panel to show only open (unresolved) comments to track remaining action items.
Are there any limitations to this method?
Every method has trade-offs. Free built-in tools (Edge, Preview) cannot edit existing PDF text — they only add annotations or new text boxes. LibreOffice may shift complex layouts (tables, columns, images) when importing PDFs. Online tools introduce privacy risks by processing files on external servers. Desktop editors offer the most complete feature set but require a one-time purchase. For each specific task above, we have noted the most significant limitation — choose the method whose limitations you can accept for your document type. Tested on: Windows 11 24H2, macOS 15 Sequoia, PDF Agile v4.x, LibreOffice 24.x.