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How to Annotate a PDF

Aug 29 2023

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Read time

4.5 min



Annotate PDF

Read time

4.5 min

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Do you deal with digital documents daily? If so, then the ability to add personal insights or highlight key points is a necessity. No doubt that you’ve had the need to make a note for yourself while reading a PDF!

If you’re a student or an educator, for instance, youneed a way to study effectively from PDF textbooks or a way to mark and review digital research assignments. Marking up PDF pages or PDF text directly changes how you engage with your content, interact with course material, and collaborate on digital documents.

And this is where a PDF annotator tool comes into play.

From inserting text to adding comments, Xodo’s Annotate PDF tool has you covered. See how you can annotate and comment on your documents instantly and with ease.

How to Annotate a PDF  

Here’s how to annotate PDF online with Xodo:

1. Upload your PDF to Xodo’s PDF Annotator tool.

2. Use any of Xodo’s annotating tools by selecting them from the toolbar. Then click and drag over the text you wish to annotate or click on the page where you want to insert an annotation.

Annotation options in Xodo PDF Annotator

3. Once you’re done annotating your PDF document, click on Download or save your annotated PDF to Xodo Drive or Google Drive.

Annotation features in detail

Combined with a quick and easy annotation process, the Xodo’s PDF Annotator comes with a wide range of annotating tools that can fit any need you may have. Let’s take a closer look.


One of the most common PDF markup tools you’ll find is the PDF highlighter tool. To add a highlight to your PDF, select your highlighter colour. Then click and drag over the text to highlight the text you want.

Highlight text in a PDF in Xodo’s PDF annotator

Customize the appearance of your annotations

We should mention here that with every annotation, you have the ability to choose and customize the colour and have up to four up front and center for you to instantly access. Simply click on the drop-down arrow in the highlight colour section of the toolbar. Select your colour or custom colour and your opacity and you're good to go.

Xodo’s annotation colour options

Squiggly, Strikethrough, Underline

To add squiggly underlines, strike throughs and straight underlines, click on any of the buttons in the toolbar and then click and drag over the text you wish to annotate.

Underline, squiggly line, and strikethrough annotations

Inserting notes

With Xodo, you can easily insert personal notes into sections or paragraphs. To do this, click on the note icon from the toolbar and then click on the page where you want to insert your note. You can then jot down your own thoughts in the comments panel that’ll open in the right-hand side panel.

Inserting a note annotation with comments 

Add and customize text

When you annotate PDF content, adding text directly to the page is one of the main tasks you would expect to perform. Well, you can do that with Xodo. Simply click on the T icon and click on the page where you want to add free text. 

You can then type in your text and from the context hover menu. You can even access custom options to edit PDF text annotations you make just the way you want them to appear on the page.

Customizing added text to a PDF document

Focus on sections by adding rectangles around content

If you’re the type of person who likes to make sections pop out by drawing around it, Xodo accommodates that note-taking habit, as well. You can draw an outline around your text by clicking on the rectangle icon then clicking and dragging around the section of text. You’ll also be able to customize rectangular annotations by selecting a colour, fill, or stroke width.

Inserting a rectangular annotation around sections of text

Add comments to annotations

On top of all the annotations you can add, you’re also able to attach your comments to any of them that you wish to clarify or explain. Simply click on the annotation on the page and then add your comment in the side panel. Then click on the Save button.

Add comments to an annotation in Xodo

Quickly annotate your PDF with Xodo online

Our PDF annotator emerges as an invaluable asset when it comes to document revision and collaboration. Xodo’s range of annotation tools lets you transform static PDFs into a document for sharing ideas, feedback, and insights.

Xodo Pro can cater to a multitude of annotation needs - highlight, comment, underline, insert notes, and more, all while being able to customize them. You get a new dimension of engagement with your PDFs.

With Xodo, your PDFs transcend mere static files and become living documents, fostering collaboration, understanding, and productivity. Unlock a new level of interaction with your digital content.

Start Annotating PDFs With Xodo
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Reena Cruz

PDF Productivity Expert

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