How to Annotate a PDF on All Devices?

how to annotate a pdf

The right annotations, placed on the right place, on a PDF can help you be more productive. When working with a team, annotations make it much easier for you and your team to collaborate on the same document. In this article, we will show you the methods you can use to annotate PDF documents on all your devices.

What Are Annotations and Why Are They Important?

Simply defined, the term “Annotation” refers to marking a paragraph, page, or a sentence. You can opt to mark your PDF via underlining a sentence, adding a comment with an arrow, using a highlighter to highlight part of the text available on the PDF document, flagging the content with a symbol, drawing a shape around the text you are interested in, etc.

Annotations have a wide range of benefits. The most popular benefits include:

  • It can help improve your reading comprehension.
  • It can help you connect ideas.
  • It makes it possible for you to jot down reactions.
  • It allows you to filter some important details or points for recall and research.
  • It makes it possible for you to visualize the information in a better way.
  • As mentioned earlier on, it allows collaboration.

Basically, the concept of annotation stays the same regardless of the method you decide to use. All the methods have the same benefits. However, the tools used to annotate PDF Windows/Mac do vary. In the section that follows, you will learn how to annotate a PDF on both macOS and Windows PC using different tools.

How to Annotate a PDF on Windows, Mac, and Mobile Devices?

1.    Annotate PDF on Mac Using Preview

If your computer is running on macOS, you should have the Preview tool on it. The tool is 100% free and also extremely easy to use. The steps outlined below will show you how to annotate a PDF on Mac using Preview:

Step 1: Open the PDF file you would like to annotate in Preview. If Preview is the default PDF viewer on your computer, simply double click the PDF file. If Preview is not your default PDF viewer, right-click on the PDF document > hover the cursor over the Open With… option > choose Preview.

Step 2: Head to the menu bar available at the top of the screen and then select Tools > Annotate. In the Annotate menu, choose the Highlight Text option – this should add the annotation toolbar to your Preview window and also give you the capability to highlight any text in your opened PDF file. You can highlight a section of the text and then right-click the section to see the options which allow you to change the highlight colors or to Add Note.

annotate pdf on mac with preview

Step 3: Go back to the Annotate menu and you should be able to see an option that allows you to create a Note. The note will be a small block of color that expands into a full note to show what you had written in it. You can place the block anywhere you would want on your PDF document. Other options you can use to Annotate your document include Speech Bubbles and Textboxes.

2.    Use PDF Expert to Annotate PDF on Mac

Unlike Preview, PDF Expert is not available by default on Mac. You will need to download and install it. While the tool is not completely free, it does have a free trial version. However, to enjoy all the features offered by the PDF tool, you will need to upgrade to the paid version at some point. The tool is ideal for people who work with PDF tools on a regular basis – it has a lot of PDF file editing features.

Below, we will show you how to annotate a PDF on Mac using the numerous options available on PDF Expert:

Step 1: Open the PDF document in PDF Expert. Simply right-click on the document > select Open With > Choose PDF Expert. PDF Expert should appear as an option after you install it on your computer.

Step 2: Select the pencil tool on the bar that appears at the top of the page. This should give a set of annotation styles.

Step 3: Choose the annotation option you would like to use. For example, to highlight the text, you can choose to underline it, use strikethrough or use color. You can select the comment icon to add a note to the document.

Step 4: If you choose to highlight the text, you will just need to drag your mouse over the text. If you would like to add a note, you will simply need to click on the space where you want your note to appear and then type your text in the note box.

Step 5: Once you are done with annotating your PDF file, you can go ahead and save it.

3.    Use Microsoft Edge to Annotate PDF Files on Windows PC

Microsoft Edge has managed to become the first browser allowing PDF annotations natively. The Windows 10 Fall Creators Update brought about PDF annotation, notes, and highlights. Microsoft Edge also has the Inking feature which allows the annotation of websites, PDFs, and EPUBS – the Inking feature is more ideal for touch screen devices.

To learn how to annotate a PDF on Windows 10 using Microsoft Edge, you will need to follow the steps we have outlined below:

Step 1: Locate the PDF document in your File Explorer. Right-click on the document > hover over Open With > choose Microsoft Edge.

Step 2: Using your mouse, highlight the text you are interested in. This should display the annotation menu which has 4 options:

  • You can choose the color for the highlighter
  • You can add a note
  • Copy the selected text
  • Open the Cortana button to search the highlighted text

Step 3: To use the inking options, tap the Add Notes button (available to the left of the Share button). Select the Ballpoint Pen, Eraser, Text Highlighter, or the Touch Writing tool to mark up your PDF. You can always choose the color from the palette under the icon for the Ballpoint pen.

4.    Annotate PDF on Windows/Mac Using Adobe Acrobat

If you do work with PDFs regularly, chances are, you have already invested in Adobe Acrobat. If you are not looking to use Adobe Acrobat regularly, you can always use its free trial version which lasts for seven days. Compared to the tools available in this article, Adobe Acrobat offers more in-depth annotations.

To learn how to annotate PDF on Mac or Windows using Adobe Acrobat, you will need to follow the steps we have outlined below:

Step 1: Install Adobe Acrobat on your computer. Open your PDF with Adobe Acrobat – for this, right-click on the PDF document > select Open with > Adobe Acrobat.

Step 2: On the menu available at the top, select Tools > Comment. This will open up the Comment toolbar – you will use this toolbar for annotation.

Step 3: To the far-left corner, tap the Sticky Note icon and then click anywhere on your PDF file – this will allow you to create a sticky note that can be opened via clicking on it. After typing the comment in the Sticky Note tool, hit the Post option. 

Step 4: If your goal is to highlight the text and not add a note, choose one of the icons with a “T” in them. You can create objects by clicking on the polygon icon.

Step 5: After you are done with annotating your document, be sure to save it to avoid losing the annotations.

5.    Use Adobe Reader to Annotate a PDF Document

Adobe Reader is an ideal tool for viewing PDF files on both computers and mobile devices. With this free tool, annotating PDF files becomes extremely easy. Below, we will show you how to annotate a PDF on your computer (macOS and Windows) and mobile device (iOS and Android) using Adobe Reader.

Note: PDF annotation is only possible with Adobe Reader (XI) and later.

On Your PC or Mac

Step 1: Locate the PDF file you would like to annotate and open it with Adobe Reader (XI) and later. For this, you will need to simply right-click the file > select Open With > select Adobe Reader.

Step 2: Tap the Comment button (this should be available to the top-right). Alternatively, you can select it from the apps menu bar by visiting View > Comment > Annotations. A commenting pane should appear to the right of the screen.

Step 3: Under the Annotations heading, choose an ideal annotation tool and then proceed to annotate your document. If your goal is to draw lines, you will need to choose the tools which appear under the Drawing Markups heading.

On Mobile Devices

Step 1: Open the PDF document using the Adobe Reader application.

Step 2: Tap the top of your device’s screen to reveal the Application toolbar. Click the Annotation icon – this should look like comment and pencil icons put together.

Step 3: Select the tool you would like to annotate your document with – highlight, comment, text/pen, underline, strikethrough, etc.

Step 4: Create the annotation by drawing on your chosen section.

Step 5: Hit save (available to the top-right) to store your changes.

6.    Annotate PDF Windows/Mac Online

If the document you would like to annotate does not feature any private and confidential information, you can use online tools to annotate it. Online tools are recommended for non-private and non-confidential documents since you won’t be able to control who can view the document after you upload it to a third-party server. The good thing about using online tools is that they are not limited to one operating system – as long as the operating system you are using has a web browser, you can always use the online tools.

Below, we will show you how to annotate a PDF online.

Annotate PDF Windows/Mac Using is ideal for annotating all types of PDF documents. The tool allows you to upload the document you would like to annotate from your local hard disk and from the cloud. The supported cloud platforms include Dropbox, Box, and Microsoft OneDrive. The online tool is 100% free.

Below, we have the steps you will need to follow to use this online tool:

Step 1: Visit and upload your PDF file.

Step 2: Follow the on-screen instructions to annotate your document.

Step 3: Once you are done, you can proceed to Print, Email, Fax, or Export the document.

Annotate PDF Windows/Mac Using is free as long as the PDF file you choose to annotate does not exceed 10 MB or 100 pages. If your document exceeds this limit, you will have to pay $2.99 per month – this subscription fee comes with other benefits, including allowing you to open your files and continue with editing them from where you had left.

To use, you will need to follow the steps outlined below:

Step 1: Visit and choose the option that allows you to upload a PDF file. You can then click the Upload button or simply drag and drop the file on the popup that appears. Once the file upload is complete, will open it automatically.

Step 2: Once the PDF document opens, select Annotate on the left-hand column.

Step 3: Under Annotate, you can choose from different annotation options – Sticky Note, Highlight, Strikeout, Insert, Underline, Rectangle, etc. Select one option and then annotate your document as needed.

Step 4: After annotating your document, you will simply need to Save it and Download it. To do this, click the double, down arrows in a green box – these are available on the left-hand column.


If you would like to annotate a PDF document, the tools listed in this article should come in handy. While we have included paid tools in the article, you do not have to pay to annotate your document – you can always opt to use the free tools. The paid tools will be more ideal for people who work with PDF files on a regular basis.

Author: Treyton Collins

A tech editor for offering professional how-to articles for Windows, Android and Apple users.