Before the prevalence of digital documents, people could only rely on traditional paper and pens to make notes. The trend has shifted to digital documents, especially since PDF has gained more popularity.

Users may occasionally need to mark out a particular word or paragraph on a PDF when reading, editing, and proofreading. Therefore, if you wonder how to highlight a PDF on Windows and Mac, the following helpful PDF editors can lend a hand.

How to Highlight a PDF with Desktop Programs

If you regularly work on personal computers, this part may be of enormous help as this section centers around how to quickly mark, highlight, cross out a PDF file.

How to Highlight a PDF on Windows

If you’re looking for a solution to make notes on PDF file, such as highlight, on Windows 10, 8, and 7, many professional PDF editors can help you annotate a PDF with a few steps.

SwifDoo PDF

SwifDoo PDF has integrated ten more annotation tools to make your PDF documents more interactive as a feature-rich PDF editor. Senders can highlight, underline, and strikethrough PDF as well as add caret and shapes to the PDF with the help of SwifDoo PDF. Read on to know how to highlight a PDF on Windows:

Step 1: Download and install SwifDoo PDF from the official website;

Step 2: Launch the program and upload a PDF that needs highlight;

Step 3: Click on the Annotate and choose Highlight.

Step 4: Place your cursor at the sentence which needs to be highlighted, and then select Save to maintain all the changes. If you highlight a wrong area, right-click on the area and choose Delete or Undo on the top left corner.

Tips:The default color for the highlighted area is red, users can click on the Highlight drop-down menu to change the color.  


Apart from standard PDFs, SwifDoo PDF can highlight a scanned PDF. Since scanned PDF cannot be edited or modified, users should use the OCR feature to highlight a scanned PDF on Windows. Here are the steps:

Step 1: Open a scanned PDF with SwifDoo PDF (SwifDoo PDF will automatically detect whether this PDF is scanned or not);

Step 2: If it is a scanned PDF, you will see the notification bar shown below. Click Apply OCR to make this scanned PDF editable;


Step 3: Choose Searchable Text and Images (non-editable) in Output methods. To ensure higher accuracy of OCR results, users can choose the language of the original scanned PDF document;

                                                                    Free Download

Step 4: When ready, highlight the text on the scanned PDF.

Note:If you are required to highlight a secured PDF, make sure you have the opening password in hand. Otherwise, give up highlighting the password protected PDF.


How to Highlight a PDF on Mac

Thanks to the built-in PDF viewer - Preview, Mac users don’t have to turn to any third-party software to highlight a PDF. This natural inbuilt PDF annotator allows macOS users to highlight, underline, and strike out text in a PDF. Here’s how to highlight a PDF on Mac devices:


Step 1: Open a PDF using Preview;

Step 2: Click on the Highlight button with a pen icon and select text to mark the text in a PDF;

Step 3: Choose the down arrow next to the Highlight button to change the highlight color, underline, or strikethrough.

For creating a better user experience, Preview enables users to view and access all the highlights in a PDF. Users need to select “View” to view the thumbnail of this PDF and then click “Highlights and Notes” once users need to manage all the highlights, such as deleting and editing.

How to Highlight a PDF Online

Everybody loves freeware, and given that you don’t want to spend money on any paid PDF service, free PDF annotator seems to be a good solution. This section will introduce some free online PDF tools to help you highlight a PDF document free of charge.

Google Drive

Well, most of us consider Google Drive as a cloud platform that can provide free space for storing different kinds of files and rarely think of it as a free PDF editor. The fact is Google Drive has integrated some third-party PDF editors to allow its users to access basic PDF features, such as editing, commenting, and converting.

Step 1: Log in your Google Drive with your Google account, and right click on a PDF to choose Open with;


Step 2: Choose DocHub or Google Docs to highlight the PDF. After that, you will be directed to another page where you can leave your marks on. Optionally, you can click Connect more apps to look for more PDF apps in Google Workplace Marketplace;


Step 3: Type PDF on the search bar and download Smallpdf (let’s take it as an example). Open the PDF with Smallpdf. Choose the Text Highlighter in Highlight. When finished, click Save to Google Drive in the DOWNLOAD drop-down menu on the top right corner. Your highlighted PDF will be automatically saved into your Google Drive space.


Google Drive is actually a cloud storage service provider, which cannot edit or highlight any digital documents. That’s why it allows for integration with other free PDF tools, such as Lumin PDF, Smallpdf, DocHub, Sejda PDF, to perform highlighting on a PDF file.

Some users may wonder if it is possible to highlight a PDF in Google Chrome. The answer is yes, but Chrome needs some extensions to enable highlighting PDF documents. But the process may be too tricky to handle. Here we recommend another web-based PDF highlighter - PDF 24 Tools.


It is an all-in-one internet-based PDF highlighter, allowing user to view, convert, edit, reorder, annotate, and password-protect PDF files. As a comprehensive PDF annotator, pdfFiller can highlight, strikethrough, underline, add lines, stamps, and measure the PDF. Take a closer look at how to utilize pdfFiller to highlight a PDF online:

Step 1: Type the URL on the search bar, and upload a PDF to the workplace;

Step 2: After the PDF is loaded, choose Highlight on the main menu;

Step 3: Put your mouse at the place to start highlighting this PDF.


Please note that pdfFiller only provides a rectangular highlight tool, and users can customize the color of the highlighted area. On top of that, if you want to know how to highlight a PDF on Android and iOS, Smallpdf and pdfFiller are available on Google Play and App Store, and these two apps prove to be useful when it comes to highlighting a PDF file.

Final Thoughts

In conclusion, if you need a feature-rich PDF highlighter, SwifDoo PDF is a good choice as it can process scanned copies. As for highlighting a PDF file with online tools, Smallpdf and pdfFiller are two reliable programs. When using web-based tools, users should pay attention to the free task per day. Most online PDF tools have limited free tasks, for instance, two free chances every 24 hours.

Common FAQ about How to Highlight a PDF on Windows and Mac

Q:How do I highlight text in a PDF with Adobe?

As the leader in this industry, Adobe Acrobat provides features to highlight, underline, strikethrough text in the PDF. With a few steps, your text will be marked up:

Step 1: Upload a PDF to Adobe Acrobat, and then select Tools to choose Comment;

Step 2: Click on the Highlight Text tool (shown as a pen) to highlight text within the PDF

Adobe enables users to change the appearance of the highlighted area, such as color and opacity.


Roche has been an active PDF user for 6 years and tried different types of professional PDF tools (both online and desktop version) since at his bachelor degree. Now, Roche works as a columnist for SwifDoo PDF over the course of the last one year, and provides useful and practical solutions pertaining to various PDF topics for users from different features.