All Resources
All Things PDF

How to Annotate a PDF on Mac

Sometimes you don’t need to directly make changes in a PDF —but you do need to leave some notes. If that’s the case with you, there are ways to use the “Preview” function on your Mac to markup a PDF, provide feedback, or even simply jot down notes that you can refer to later.

The “Markup” toolbar is a nice solution for a team that needs to work on a PDF together. But how can you annotate a PDF with other tools that will make collaboration even easier? Let’s look through the specific steps below.

Adding Annotation to a PDF Document with Your Mac

Let’s start by defining an annotation. This is any sort of note, object, or highlight that supplements the PDF for your reference. And the most obvious style of annotation is simply to add a textual note to a PDF, the same way you might add a comment in Word or a Google Doc. Here’s how you do it.

  • Open Nitro PDF Pro for Mac. Click the Down Arrow next to the Annotate button to reveal the toolbar for annotating your document.
  • Select the Text tool.
  • You now have an option for inserting a text box.
Annotate Example

  • You have two options here. Click anywhere on the page to insert a text box. You’ll notice that when you start typing, the box will automatically expand to meet the text you have. Or you can click and drag to create a text box with a specific size. In this case, the software will wrap the text to the size of the box.

This is a simple way to add text directly to your PDF. But keep in mind that if you don’t want to interfere with the text itself, you may want to insert a Note instead.

Adding a Note to a PDF on Mac

A note comes with a collapsible text box, with a little indication in the PDF that there is a note to read. This is great for anyone who wants to share a PDF without interfering with the content. Interested readers can check out your annotations without those annotations covering up a lot of empty space within the PDF. Here’s how to add them to your document.

  • Once again, open Nitro Sign. Click the Down Arrow next to the Annotate button to reveal the toolbar for annotating your document.
  • Select the Notes tool rather than the Text tool.
  • With the Notes tool enabled, you can now click on the PDF where you’d like to place your note. (Don’t worry; you can always change the position of the note later simply by clicking and dragging). The note will be inserted as a small icon attached to a collapsible text window. Anyone who wants to read the note can simply un-collapse the window and read.
  • It’s up to you whether you want to hide the note (leave it collapsed) or reveal it (leave it uncollapsed). This is a stylistic choice on your part.
  • If you need to adjust the name on the note, go to Preferences > Editing > Name and edit the author of the note.

Adding Comments on a Shared PDF

Naturally, one of the best reasons to use annotation is when you’re sharing the document and collaborating on how it should look. As a PDF gets passed back and forth between colleagues and collaborators, you have to leave comments and feedback. Or you may have to review comments and feedback before you edit the PDF yourself.

The Comments tool is a useful way to react to the development of a PDF without interfering. It will also help everyone stay on the same page, as they know who’s commenting on what, and what needs to be done to fix the final PDF.

  • Repeat the first step above: click the down arrow next to Annotate in the toolbar to reveal the appropriate tools.
  • This time, select the Comments tool.
  • With the Comments tool enabled, click on the page location where you’d like your comment to go. Click and drag to size the comment when you place it; this may take a little bit of adjustment to get used to how it works.
  • With your comment placed in the PDF, you can type over the text. Voila! Your comment will go right in.

One further note: if you use the Edit or Select Text tool, you can still double-click a comment to edit it. You don’t always have to work with the Comment tool to edit comments you’ve already placed.

Add a “Callout” to Your PDF to Flag an Issue

It will happen at some point: you need to call an issue out (politely, of course) within a PDF to bring something to their attention. It’s easy enough to do that in online collaborative tools; why shouldn’t it also be easy to do in a PDF? Using Nitro Sign, it can be:

  • Within Nitro, repeat the same step in the other processes, clicking the Down arrow next to the Annotate button to reveal the tools.
  • Select the Callout tool.
  • As before, click the on-page location on which you’d like to place your callout text box.
  • Place the callout. You can now click and drag the sizing handles to resize the text box to your specifications.
  • Click and drag the endpoints to direct viewers to the “leader line.” This will create an arrow to the specific location on the page you’re talking about.
  • If you need to edit the call out, select the Edit tool and click on the callout. You can use the Edit tool to reposition or resize the box you’ve created.

What happens if you’ve placed a callout, but need to move it?

  • Deselect the callout. You can do this simply by clicking anywhere on the page.
  • Holding the Command key while using the Edit tool, you can now select and drag the entire callout to another location. Note: your callout will be preserved as you wrote it; you’re simply moving it.
  • Let go of the Command key to place it. You can now edit the individual components of the callout, just as you could before.

Adding a Sound Annotation to a PDF

  • Sometimes, you can’t adequately express your feedback in the written word. It may be easier for you to simply upload a sound file of yourself speaking about the issue and leaving it in the PDF. If that’s the better way to do it, here’s what you’ll want to know:
  • If you want to pre-record a file, do it now. Remember where you stored this file on your Mac.
  • Within Nitro Sign, click the down arrow next to Annotate to reveal the toolbar, as before.
  • Select the Sound tool.
  • Click on a specific page within your PDF—this is where you’ll place the sound file.
  • A menu will appear. This will give you the option of using a Red Record Button to record yourself right now, or you can use a sound file that has been previously recorded. Choose your option.

This will create a sound/audio file annotation next to the appropriate page. From then on, people collaborating on the PDF can hear the feedback you’ve left.

Tips for Annotations on Your PDF When You’re Using a Mac

  • Double-click the tool to “Lock” it into place. This lets you work with the tool continuously. This is especially useful if you know you’ll have to make a lot of notes in one working session, for example. If you want to unlock the tool, Click Edit or use Command + 2. You can also visit this feature within Preferences if you want to disable it. However, for people who are adding a lot of feedback to a PDF in one sitting, locking the tool into place is a useful way to approach it.
  • Use a callout tool when you have something specific in mind. Be wary of adding a note on a PDF when you want to highlight a specific problem. Don’t add a text box and say “On one of the lines here, we should change it…” because that’s not specific enough. Instead, use the Callout tool when you do this. This is essentially like using your finger to point to the PDF. This will help reduce confusion among anyone who’s reviewing your annotations the first time.

Ready to make the most of your annotations with PDFs? Then it’s time to use the software that makes it as easy as possible. We recommend signing up for a free trial of Nitro PDF Pro for Mac to experience everything that software can do for PDFs in the digital age.

All Things PDF Mac
Electronic Signatures
A leader in e-signatures
Nitro Sign recognized as a Leader in the 2022 GigaOm Radar Report for eSignatures. Learn more about GigaOm’s evaluation and analysis of the top eSignature vendors in the category.