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Home / Blog / How to Add Comments to PDF in 3 Free Ways [Complete Guide]

How to Add Comments to PDF in 3 Free Ways [Complete Guide]

By Susy | Follow twitter | Updated on November 11, 2022
When you review a PDF document and need to mark up the content to be modified, adding comments such as sticky notes and text to it might be essential. However, because PDF files are designed for easy sharing but not editing, it can be a headache to add comments to PDF. That’s why we write this article to help.

This post will walk you through how to add comments to a PDF on different devices with 3 software and ways to meet your different needs.

Tips for Adding Comments to PDF: Types of Comments

Basically, a comment in a file is a piece of text added to annotate the specific content, but you can add multiple types of comments to a PDF in fact. The types of comments in PDF include, but are not limited to:

  • Text
  • Sticky notes
  • Shapes with notes
  • Lines with notes

To add comments to PDFs efficiently, a handy PDF annotator is required. The software introduced in the post, such as SwifDoo PDF, is stable and easy to use. In addition to the listed comments, they also help add video, audio, and some other objects to PDFs for commenting. Read on to learn how-to.

How to Add Comments to a PDF on Windows

For those who want to add comments to PDFs with a tiny and fast program, SwifDoo PDF is worth a try. The software is available on all the recent versions of Windows, including Windows 7/8/10/11. It enables you to comment on a PDF by adding pop-up notes and carets in different colors, drawing shapes and lines, etc. More than adding comments to a PDF, it has many other distinct features allowing you to convert, secure, make direct edits to PDFs, and more.

Follow the three steps below to add comments to your PDF easily.

Step 1: Drag and drop your PDF file into the program after free downloading and launching it;


Step 2: Click the Annotate tab on the top and choose a comment tool such as Note;

How to add comments to PDF with SwifDoo PDF

Step 3: Click a place on a PDF page and add a comment to the PDF in the pop-up box.

How to add comments to PDF with SwifDoo PDF tool

When needed, you can add comments to PDFs by directly typing text on them using the “Typewriter” tool. If you have added a shape, line, or highlight in PDF, double-click on it and a comment box will appear to allow for typing your comment. By hitting a comment in PDF within the PDF software, you have the options to change its color, opacity, line type, and other properties.

Tips: The “Attachment” comment tool makes it possible to add video (or audio) comments to PDF.

After adding all necessary comments to your PDF, you can manage them in one place. To do that, click “Manage Annotations” in the “Annotate” section to open the comments panel in the left sidebar, then tap an icon or right-click on a comment to edit, reply, or delete it. Using the PDF software, you can print the added comments with your PDF file.

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After exploring how to add comments to a PDF file on Windows, let's keep reading to learn how to do the same thing on Mac next.

How to Add Comments to a PDF on Mac

If you don’t know how to add comments in a PDF on Mac, the Mac and iOS-based PDF annotator - PDF Expert, comes in handy. The free version of the software allows you to read, comment, and fill out forms in PDF. You can use your finger or the Apple Pencil to do the comment work. More advanced features such as converting PDFs require its pro version.

Learn how the PDF program makes it simple to add comments to PDF for free.

Step 1: Open your PDF file with the PDF annotator and choose Annotate on the top menu bar;

How to add comments to PDF on Mac with PDF Expert | SwifDoo Blog

Step 2: Select Note, Highlight, Pen, or another tool in the drop-down toolbar;

Step 3: Tap a position on a PDF page and enter text in the comment box. Repeat the steps to add more comments to the PDF on your Mac.

Compared to desktop software, web applications sometimes may be more convenient to access. Find out which online tool to use and how it helps add a comment to your PDF in the coming part.

How to Add Comments to a PDF Online

Another free way to add comments to PDF is using an online tool, PDF4me. The software is developed to streamline your review work with a series of comment tools. It also comes with PDF conversion, compression, combination, and a variety of other capabilities.

Take a quick look at how to add comments to a PDF online for free.

Step 1: Access the online tool in your browser and click Edit on the top of its website;

Step 2: Tap Select File to upload your PDF;

Step 3: Use the comment tools in the left sidebar to add comments.

How to add comments to PDF online with PDF4me | SwifDoo Blog

The online PDF software enables you to add notes, text, lines, stamps, and other comments in PDF. It is easy to use but only allows you to process one file per hour. Compared to desktop software, it runs slower.


All three PDF software allow you to add common comments such as bubble comments to PDFs for free. Among them, SwifDoo PDF enables you to add much more types of comments, including videos and audio. Importantly, after comment, you can review and manage all them in the sidebar quickly. Get it for a 15-day free trial and you are able to test all the features.

With respect to how to add comments on PDFs using other tools, navigate to SwifDoo PDF's blog page to get more top PDF annotators on the market.

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Common FAQ about How to Add Comments to PDF in 3 Free Ways [Complete Guide]

Q:How do you add comments to PDF in Adobe Reader PDF program?

To add comments to a PDF file in Adobe Reader, open your PDF with the software, select "Tools" > "Comment", and use the comment tools in the pop-up toolbar to do your work.

Q:Why can't I add comments to a PDF?

If you can't make comments on a PDF but can do that with some other PDFs, it is probably because the PDF file is password protected from unauthorized editing. Regarding how to add comments to a secured PDF file, enable editing by offering the correct password in PDF software or remove the password from the protected PDF to comment.

Q:Can people see comments in PDF?

When you send a PDF document with comments to other people, the recipients can see the comments just like you can in a PDF annotator. Therefore, multiple people can add comments in a PDF for collaboration. Please note that the built-in PDF reader in any browser won't let you check the audio or video comments.



Susy has worked with PDF tools for more than 5 years. During the past time, PDF software is of huge assistance in increasing her productivity. She joined SwifDoo PDF one year ago and works as an editor now. Based on a lot of research and tests, Susy can offer users professional and practical solutions to PDF issues.

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