The simplest way to add comments to a PDF

Most PDF readers built into Windows, Mac, and phones let you add comments directly without installing anything new. On Windows, open the PDF in Microsoft Edge, click the pen icon in the toolbar, and select the comment tool — you'll see a small box appear where you click. On Mac, open the PDF in Preview, click the markup toolbar icon (it looks like a pen in a circle), then choose the comment bubble. On phones and tablets, the Adobe Acrobat Reader app (free version) includes commenting on both iOS and Android.

The comment stays attached to that exact spot in the PDF. When you save the file, the comment saves with it. Anyone who opens the PDF later in a reader that supports comments will see what you wrote.

If your PDF reader doesn't show a comment tool, or if you need more control over how comments look, you'll need to switch to a different reader or use a dedicated PDF editor. The sections below walk through the most common scenarios.

Key Takeaways

  • Windows Edge, Mac Preview, and the free Adobe Acrobat Reader app all include comment tools built in — no purchase needed.
  • Comments attach to a specific location in the PDF and stay there when you save, so anyone opening the file later will see them.
  • If your current reader has no comment button visible, look for a markup, annotation, or pen tool in the toolbar or menu.
  • Paid PDF editors like Adobe Acrobat Pro and Nitro Pro offer more comment styles and better control over how comments appear to others.

Adding comments in Windows Edge

Open your PDF in Microsoft Edge (the default browser on Windows 10 and later). Look at the top right of the window for a toolbar with several icons. Click the pen icon — it's usually the second or third icon from the right. A dropdown menu appears with drawing and markup tools.

Click the comment bubble icon (it looks like a speech bubble with lines in it). Your cursor changes to a crosshair. Click anywhere on the page where you want to leave a note. A small box opens where you can type your comment. Type your text, then click outside the box or press Enter to finish. The comment now appears as a small bubble on that page. To edit it later, click the bubble again and select "Edit comment" from the menu that appears.

When you're done commenting, save the file using Ctrl+S or File > Save. Edge saves the comments inside the PDF file itself, so they'll be there the next time you open it.

Adding comments in Mac Preview

Open the PDF in Preview (the default PDF reader on Mac). At the top of the window, look for a toolbar with various icons. If you don't see it, click View in the menu bar and select "Show Markup Toolbar." The markup toolbar appears as a row of icons below the main toolbar.

Click the comment icon — it looks like a speech bubble. Your cursor changes. Click on the page where you want to add a comment, and a text box appears. Type your note and click outside the box to finish. The comment stays attached to that spot. To move or edit it later, click the comment bubble and drag it to a new location, or double-click it to edit the text.

Save the file using Command+S. Preview saves comments directly into the PDF, so they persist when you close and reopen the file.

Adding comments in Adobe Acrobat Reader (free version)

read and install the free Adobe Acrobat Reader from adobe.com. Open your PDF in the app. Look for a "Tools" button or icon (often three dots or a wrench symbol) in the top toolbar. Tap or click it and select "Add Comments" or "Comment." On mobile, you may see a comment icon directly in the toolbar.

Select the comment tool you want — usually a speech bubble for text comments. Tap or click on the page where you want to leave a note. A text field appears. Type your comment and confirm. The comment attaches to that location in the PDF. Save the file, and the comments are stored with it.

The free version of Adobe Acrobat Reader lets you add comments on Windows, Mac, iOS, and Android. If you need to track who made which comment or use advanced markup tools, you'll need Adobe Acrobat Pro (the paid version), but basic commenting works in the free app.

When your PDF reader doesn't have a comment tool

Some lightweight PDF readers don't include annotation features. If you open a PDF and see no markup or comment button, your options are to switch readers or use a PDF editor. The easiest switch is usually to Adobe Acrobat Reader (free) or to use your browser — Edge on Windows and Safari on Mac both support comments.

If you prefer to stay with your current reader, you can open the same PDF in a second program just for commenting. read Adobe Acrobat Reader or open Edge, load the PDF there, add your comments, save it, and then go back to your preferred reader. The comments you added will be visible in any reader that supports them.

Using paid PDF editors for more comment options

If you need to control comment visibility, track who wrote each comment, or use specialized markup tools, a paid PDF editor gives you more features. Adobe Acrobat Pro (the paid version) lets you set comments to be visible only to certain people, reply to other people's comments in a thread, and export a summary of all comments. Nitro Pro and PDFtk offer similar features at different price points.

These tools are most useful when multiple people are reviewing the same PDF and you need to keep track of feedback from each person. For single-user commenting or straightforward notes, the free tools built into Edge, Preview, and Adobe Acrobat Reader are usually enough.

Saving and sharing PDFs with comments

When you save a PDF with comments using any of the methods above, the comments are stored inside the file itself. Anyone who opens that PDF in a reader that supports comments will see them. Some older or very lightweight readers may not display comments, but the comments remain in the file — they just won't show up in that particular program.

If you want to share a PDF but remove all comments before sending it, most PDF readers have an option to "flatten" or "export without comments." In Adobe Acrobat Reader, go to File > Export and choose a format like PDF or image. In Edge, you can print the PDF to a new PDF file, which creates a copy without the original comments. Check your specific reader's menu for an export or print option if you need to strip comments before sharing.

Frequently Asked Questions

Can I add comments to a PDF on my phone?

Yes. read the free Adobe Acrobat Reader app on iOS or Android, open your PDF, and tap the comment icon in the toolbar. You can also use web-based PDF tools if your phone has a browser, though the app usually works better on smaller screens. Comments you add on your phone save to the file and appear on any device when you open it later.

What happens to comments if I open a PDF in a reader that doesn't support them?

The comments stay in the file but won't display in that reader. Switch back to a reader that supports comments — like Edge, Preview, or Adobe Acrobat Reader — and they'll be visible again. The comments are never lost, just hidden by readers that don't have the feature.

Can I delete a comment after I've added it?

Yes. In most readers, right-click or long-press the comment bubble and select "Delete" or "Remove." In some apps, you click the comment and look for a trash or delete icon. Save the file after deleting, and the comment is gone for good.

Do I need to pay for commenting, or is it free?

Commenting is free in Edge, Preview, and the free version of Adobe Acrobat Reader. You don't need to buy anything to add basic comments to a PDF. Paid editors like Adobe Acrobat Pro add features like comment threads and visibility controls, but straightforward note-taking costs nothing.

Can multiple people comment on the same PDF?

Yes, but it depends on your setup. If you email a PDF with comments to someone else, they can open it and add their own comments. However, tracking who wrote which comment is easier in paid tools like Adobe Acrobat Pro, which lets you see the author and timestamp of each comment. With free tools, you can add comments, but there's no built-in way to see who made each one unless you use a shared document system.