How to annotate a PDF

Additionally, annotating a PDF doesn't require expensive software or complicated workarounds. This guide shows you how to highlight, comment, draw and mark up any PDF, whether you're on a browser, Mac or Windows PC.

Method 1: Annotate a PDF online using Lumin

Lumin's Annotator PDF tool lets you annotate any PDF directly in your browser with no download required. You can highlight text, add comments, underline or strikethrough content, and draw freehand on any page.

Here's how to annotate your PDF with Lumin:

1. Open Lumin's free PDF Annotator tool and upload your PDF.
2. The Draw tool will be selected automatically from the toolbar.
3. If the Draw tool does not open automatically, click the Markup tool in the toolbar. 
4. From there, you can choose annotation options such as Highlight, Underline, Strikethrough, Comment or Freehand Draw.
5. Apply your annotations directly on the document.
6. When you're done, click the download icon to save your annotated PDF to your device.

Method 2: Annotate a PDF on Mac using Preview

If you're on a Mac, Preview is a free built-in option for basic PDF annotation. It supports highlights, text boxes, shapes and freehand drawing, which covers most everyday markup needs.

To annotate a PDF in Preview:

1. Open your PDF in Preview (right-click the file and select "Open with" > "Preview").
2. Click the pencil icon or go to View > Show Markup Toolbar.
3. Use the toolbar to highlight text, add a comment box, draw shapes, or sketch freehand.
4. Save the file using File > Save, or export it as a PDF.

Note: Preview works well for straightforward annotations, but it can't edit existing text or handle more advanced tasks like form fields or collaborative comments. For those, a dedicated PDF editor like Lumin is the better option.

Method 3: Annotate a PDF on Windows using Microsoft Edge

Windows users don't need to install anything extra. Microsoft Edge, the default Windows browser, has a built-in PDF viewer with annotation tools that let you draw, highlight and add text notes directly on a PDF.

To annotate a PDF in Microsoft Edge:

1. Open File Explorer, right-click your PDF and choose "Open with"  > "Microsoft Edge."
2. In the Edge toolbar, click the "Draw" or "Highlight" icon.
3. Select a color and apply your annotations to the document.
4. To add a typed note, use the "Add text" tool.
5. Save your annotated file by pressing Ctrl+S or clicking the save icon.

Frequently asked questions

Can I annotate a PDF for free?

Yes. Lumin's PDF editor is free to use and supports highlights, comments, underlining, strikethrough and freehand drawing. You can upload, annotate and download your PDF without creating an account, though signing up unlocks additional features. Mac users can also use Preview, and Windows users can use Microsoft Edge. Both are free and built into their respective operating systems.

How do I annotate a PDF in Chrome?

The easiest way to annotate a PDF in Chrome is to use a browser-based tool like Lumin. Open Lumin in Chrome, upload your PDF and use the annotation toolbar to add highlights, comments or drawings. Chrome's built-in PDF viewer can display annotations but doesn't let you add them, so you'll need a dedicated tool for that.

What is the best PDF annotation tool?

The best tool depends on what you need. For full annotation features like highlights, comments, freehand drawing and collaborative review, an online editor like Lumin gives you the most flexibility across any device and browser. For quick, offline markup on Mac, Preview is a reliable built-in option, and on Windows, Microsoft Edge covers the basics.

Why can't I see annotations on my PDF?

If annotations aren't visible, the PDF may have been saved without embedding the markup, or the viewer you're using doesn't support displaying annotations. Try opening the file in a dedicated PDF editor to check. If you created annotations in a tool and they've disappeared, make sure you saved the annotated version rather than the original.