How to Highlight in PDF Documents Online

PDFs are a popular document format for contracts, business reports, textbooks, course notes, research papers, and more. This is because it offers consistent formatting and you can open PDFs on nearly any electronic device, regardless of operating system.

Unfortunately, those same features can make it difficult to add annotations and highlight text on a PDF. This is great for sharing, but not so great for reviewing documents or highlighting key sections without printing.

How to Highlight a PDF Online (Free, No Signup)

Here's how to highlight any PDF in your browser:

1. Go to Smallpdf's PDF Annotator and upload your PDF.
2. Click the highlighter icon in the toolbar.
3. Choose your highlight color and opacity.
4. Drag across the text you want to highlight.
5. Download your highlighted PDF.

The highlighter icon lets you highlight your document freehand. You can even choose how thick you want your highlights to be.

You can also highlight text in your PDF by selecting the “Highlight text” option. With this option, you can still select the color and opacity, but the thickness is always the same size as the text you are highlighting. And you aren't limited to the six colors shown by default. Click the plus icon to choose a custom color.

How to Highlight a PDF on Mac with Preview

Mac users can highlight PDFs using the built-in Preview app without downloading any software:

1. Open your PDF file in Preview (double-click the PDF or right-click and select “Open with Preview”).
2. Click the Markup Toolbar icon (pen tip in a circle) or press Shift + Command + A.
3. Select the Highlight button (highlighter icon) and choose your color from the dropdown.
4. Drag over the text you want to highlight, then save your file.

Tip: Use Command + Control + H as a keyboard shortcut to quickly access the highlighter tool.

How to Highlight a PDF on Windows with Microsoft Edge

Windows users can highlight PDFs directly in Microsoft Edge browser:

1. Open your PDF in Microsoft Edge (drag and drop the file into Edge, or right-click and “Open with Edge”).
2. Click the Draw tab in the top toolbar to access the annotations toolbar.
3. Select the highlighter tool and choose your preferred color.
4. Drag over the text to highlight, then click the Save icon or press Ctrl + S.

Note: If you don't see highlighting options, you may need to enable PDF annotations in Edge settings.

How to Annotate PDF Documents

PDF Annotator allows you to add blocks of text, shapes, and images to PDF files. Use the pencil tool to draw on your PDFs freehand.

You’ll find these tools in the same toolbar as the highlighter, and most offer a range of customizations. There is an eraser too, for removing or tidying up any scribbles you made using the pencil.

Manage Your PDF Highlights

Once you've added highlights, you might need to adjust colors, remove mistakes, or review all your highlights at once.

How to Change Highlight Color in a PDF

If you need to change the highlight color in a PDF online, Smallpdf's PDF Annotator makes it simple and stress-free. Just click on the highlighted text to bring up the properties bar. You'll see two options: “Border color” and “Opacity.” Click “Border color” to pick a new shade that works for you. Choose from preset colors or use the custom picker to find the perfect shade.

How to Remove Highlights From a PDF

1. Open your PDF file with highlighted content in PDF Annotator.
2. Use the Select tool, and click on the highlighted area of text and delete.
3. Repeat for any other highlights you want to remove.
4. Download or export your PDF once you are done.

With PDF Annotator, you can remove highlights and annotations added using other PDF software—or even change the highlight color in a PDF if you'd prefer to adjust them instead.

Beyond Highlighting: What Else Can You Do with PDFs?

Highlighting is just the beginning. With Smallpdf, you can also:

• Add sticky notes and comments
• Draw shapes and arrows
• Merge or split PDFs
• Convert PDFs to Word, Excel, or PowerPoint

Start your free trial to access all Smallpdf tools.

PDF annotation is not the same as editing a PDF, and you should never use it for making changes in a document. Annotation is for adding notes, comments, questions, and summaries to a document.

Speaking of summaries, you can use our AI PDF Summarizer to generate summaries of your documents, which you can then add as annotations.

Frequently Asked Questions

Why can’t I highlight text in my PDF?

If you can't highlight text, your PDF might be a scanned image rather than searchable text. You'll need to use OCR (Optical Character Recognition) to convert the image to text first or use a freehand highlighting tool to mark over the text visually.

How do I print a PDF with highlights?

Most PDF viewers will print highlights by default. In your print settings, make sure “Print annotations” or “Print markup” is enabled to include your highlights on the printed page.

What’s the difference between highlighting and annotating?

Highlighting marks text with color for emphasis, while annotating includes adding comments, notes, shapes, or other markup. Highlighting is one type of annotation, but annotation encompasses much more.