Annotating a PDF is the best way to share feedback and ideas, and collaborate with friends and co-workers. 

But if you’re struggling to annotate PDFs effectively because the process is complicated, we’ve got you covered. 

In this article, we’ll break down how to annotate on PDFs online and offline.

But before we delve into the specifics, let’s look at what a PDF annotation is. 

What is PDF annotation?

Annotation is a fancy way to say you’re adding notes or highlighting important points in a PDF document. 

You can do it for your reference or use it to break down important information for your readers. Here are a few ways you can annotate your PDF document:

• Highlight or underline important text.
• Add comments to margins. 
• Insert digital sticky notes. 
• Add images to explain a specific concept.

In short, you’d add digital highlights and drawings to your eBook or PDF document instead of running a highlighter, writing in the margins, and creating rough sketches. 

How are PDF annotation files useful?

Adding markups to a document when you’re reading it helps you comprehend the information you’re consuming and keep track of it seamlessly. 

It’ll ensure you won’t read five pages and realize you lost track of what the author said three pages ago. 

Instead, you’ll read actively and comprehend information easily as annotations help you connect ideas and visualize concepts quickly. 

But remember that annotations are effective only when done sparingly. So, ensure you highlight only the important points, not the whole document. 

Next, let’s look at a few ways to annotate PDFs easily. 

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How to annotate a PDF on Windows using Adobe Acrobat

Adobe Acrobat is everyone’s go-to software to annotate PDFs easily. Since it works well on Windows (and Mac), chances are you already have it installed on your system.  

And regardless of whichever operating system you use, Adobe Acrobat offers the following annotation features:

• Text annotations
• Drawing annotations
• Sticky notes

Before we look at how to access all of these features in detail, let’s look at how you can access the tools. 

1. Open the toolbar 

First, you’ll need to make the markups and annotations toolbar visible. So, go to “Tools” and select “Comment” to open the toolbar. 

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The toolbar has all the features, and if you want clarity on what each one does, all you’ve got to do is right-click the toolbar and click “Show all Labels.” This will display the tool’s name alongside its icon to avoid confusion. 

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2. Add PDF annotations to your file

Annotations can include both text and drawing annotations 

A. Text annotations

Text annotations include:

• Highlight text
• Underline text
• Strikethrough text
• Replace text
• Insert text
• Add comments

All you’ve got to do to access these features is to simply drag your cursor through the required text and select the required tools as shown below:

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B. Drawing annotations

You can manually draw an image and erase it or use Acrobat’s toolbox to draw various shapes with drawing annotations. 

To draw an image manually, use “Draw” and “Erase Drawing” from the toolbar. And if you want to add shapes to your PDF, click the three dots next to Erase Drawing and choose a shape. 

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C. Sticky notes

To add sticky notes to your PDF, you should enable the comments feature first. Once you’ve done that, click the first tool on your toolbar to add your sticky note. 

If you’d like to resize the pop-up box, right-click on the note, select “Open Pop-up note,” and resize the box according to your preference. 

You can also change the text formatting within the sticky note and its color. To do this, simply click the three-dots symbol on the toolbar and perform the actions as shown below. 

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3. Save your file 

Here are a few different ways to save your annotations on Adobe Acrobat. 

• File > Save: To save changes to the current file.
• File > Save As: Save a copy of a PDF
• File >Save As Other > PDF Portfolio: To save a copy of a PDF Portfolio.

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If you’re using Adobe Acrobat Reader instead of Adobe Acrobat, choose File > Save As or File > Save As Other > Text.

The only caveat with using Adobe Acrobat is that it's a paid tool, and you’ve got to spend about $14.99 each month to keep using all its features. 

For free PDF annotators that have the same functionality check out Kdan’s free PDF reader on Microsoft’s online store. 

Now that we’ve looked at a free Adobe alternative for Windows let’s look at one for Mac in the next section. 

How to annotate a PDF file on Mac

1. Click the “Show Markup Toolbar” button

If you’re a Mac user, you can use Apple’s native app, Preview, to annotate your PDFs and collaborate with your team.  But before you start adding your annotations, click the Show Markup toolbar button to make your toolbar visible. 

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2. Use the tools to annotate the PDF

Similar to Adobe, Preview also offers tools to create image and text annotations on your PDF. We’ve listed some of the tools below. 

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• Add text: Use the text box to jot down important points in your document, as shown below. 

• Sticky note: Simply use the Note icon and type the text as shown below. 

• Speech bubble: Go to “Tools” and select the “Speech Bubble” option from the Annotate menu. Then, click the bubble to add text. 
  
  

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• Text highlight: If you want to highlight text, drag the cursor across the text and simply click the highlighter icon on your toolbar and use the drop-down arrow to choose the color.

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• Add shapes: You can draw shapes manually with the trackpad using the Draw or Sketch tool and add shapes to your PDF with the Shapes tool. 

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Now that we’ve looked at how to annotate PDFs offline on your computer let’s look at how you can do the same for an online document. 

3. Save the file

Preview automatically saves changes made to the PDF. But you can also click File>Save to save your PDF file. 

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How to markup PDF on Google Drive

If you want to collaborate with your team online and share feedback, Google Drive is the best option, and there are two ways to annotate a PDF using this tool. 

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A. Use Google Sheets

Annotating a document on Google Sheets is pretty straightforward. All you’ve got to do is click the “+” icon to start adding comments. 

But before that, you’ll need to click the PDF and choose “Google Sheets” from the “Open With” option. 

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Once that’s done, you can start adding comments to the document as you would normally do. 

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The biggest downside of employing this method is that it's hard to see white or light-colored text, and you've got to convert the document into a PDF and upload it, so your team views the feedback. 

Apart from being cumbersome, this process also makes version control difficult, which brings us to the second method. 

B. Use the Lumin editor 

Lumin is a third-party integration and a cloud-based PDF annotator which allows users to edit PDFs from any device. 

To start annotating PDFs on Lumin, click the PDF on your Google Drive and choose Lumin from the “Open With” option. 

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To open the editor, grant access to your Google Drive and choose the account containing the PDF if you’re using multiple Google accounts. Once the editor opens, you can annotate on the PDF as follows:

• Add comments: This feature is similar to the comments feature in Google Docs and allows you to add comments and start threads within the PDF.
  
  

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• Draw: You can use the Drawing tool to add shapes and images to your docs. The best part is that the Notes section shows visual comments on the left, so there’s no confusion.
  
  

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Conclusion

Annotating PDFs helps highlight important points or share feedback. 

There are different ways to annotate PDFs depending on your operating system. 

You can use Adobe Acrobat or Microsoft's free apps from the online store if you're a Windows user. 

But if you're a Mac user, you don't have to worry about using paid apps as it has a native PDF annotation tool called Preview. 

If you're annotating PDFs online for collaboration, you can always use Google Sheets or a third-party integration like Lumin to get the job done. 

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