10 Best Annotation Tools For PDF

by Sachin

Making notes, reviewing, commenting, marking-up…call it whatever you like, but it is a well-known fact that annotations are an integral part of most documents. But how do you find the best annotation tools for PDF files? To help you avoid the pain of searching on your own, we’ve prepared this selection of the top 10 annotations tools for PDF. This article provides an overview of note-making utilities that are user-friendly and have features that are specifically designed for making annotations and commenting on documents. Let’s begin. 

1. PDFelement: Professional PDF Editor from Wondershare

PDFelement has everything you need to make precise and clear annotations. It is essentially a PDF editor but the functionality goes far beyond that. You can “Edit PDF like Word”, as the slogan says, but you can also add images, convert files between PDF and other formats, fully edit all content types, merge and split files, add watermarks, change background color, add hyperlinks, edit headers and footers, and a lot more.

The extensive annotation feature allows you to add notes and comments, draw or add shapes, highlight, underline and strikethrough text, add text callouts, insert sticky notes, etc. These tools are also customizable. For example, you can decide the thickness of a circle or rectangle, choose the font for your comments, and even change colors from a wide range of options.

One of the best features is that these annotations and mark-ups can be hidden when not required, and shown when needed. In addition, there are custom stamps for standard text such as “Confidential”, “Sign Here”.

And other useful elements that are commonly used in PDF documents. To add an annotation or note, just go to the Comment section of the software and use any of the tools from the toolbar just below it. The clean layout will make it easy for you to find what you need. Click the element to be added and then click the document where you want it to appear. You can then edit and customize it as you like from the tool panel that will appear on the right side.


Full editing functions, a large number of annotation tools, lots of additional features like security, conversions, signature, OCR, forms management, PDF organizing, etc.

2. EndNote: Ideal Tool for Scientific Papers

We all know that academic papers and scientific journal articles require source citations. EndNote is specifically designed for this but it also has some basic note-taking capabilities. Of course, they are not as advanced as what you would find in PDFelement or Adobe Acrobat DC, but if you are a research student or a scientist writing a paper for your thesis or for a journal, the annotation tools will help you develop the content with personal notes, reminders, and other simple mark-ups.


Excellent for adding citations to scientific documents, basic annotation tools available for note-taking.

3. PDF Reader: Best PDF Viewing Tool with Annotation Features

This utility is available from the Microsoft Store and the basic version is free. However,  the functions are limited and the paid version is quite expensive. Nevertheless, if you’re looking for a good PDF reader that also has annotation capabilities, this is definitely worth a try. The interface is minimalistic and there are no distractions to take your focus away from the document. Although the annotation tools are limited, you can easily make notes, add comments, mark sections of text, and so on.


Excellent PDF reader with a reasonable selection of annotation tools.

4. Adobe Acrobat DC

This is the most widely-used PDF editor on the market today. It has been around for twenty years and has evolved into a feature-rich PDF utility with tons of functions that you won’t find in most other PDF editors. The “DC” part stands for Document Cloud, which indicates that the app is well-integrated with the cloud service provided by Adobe.

The annotation tools in Acrobat DC are extensive and easy to add to any PDF document, but customization is not as straightforward as with PDFelement. Also, some of the tools are buried deep inside the menu so they’re not that easy to find. Many users say that the interface is quite cluttered and disorganized unless you are already familiar with the software.


Popular software with robust functionality, including adding annotations. You can also export PDF annotations.

5. iWebPDF: Solid PDF Editor With Advanced Annotation Tools In The Pro Version

iWebPDF from Jinge Technologies is an overall PDF utility with functions like editing, signing, annotations, and reading. It is a fairly well-known application for form-filling and basic PDF editing, but the Pro version does offer some advanced features like PDF security and multimode reading. The annotation tool is available as a plugin and includes text annotations, shapes, highlighting, stamps, and comment boxes.


Solid PDF editor with all required annotation functions, most features are available as separate plugins, making the core software easy to install because of its small size.

6. Zhiyun Document Translation Software

As the name suggests, this is basically a language-translation tool, but it does come with some note-making capabilities. It’s easy to use and the annotation elements allow you to mark or highlight text and then add notes next to them for your reference. It’s not a super-advanced software for mark-ups but it gets the job done. The best part is actually the translation feature. Just select a portion of text and you’ll immediately see the translation there. Great for anyone working in a multilingual environment.


Accurate translation with limited but useful commenting and highlighting features.

7. CAJViewer: A PDF Reader With Advanced Note-Making Features

Essentially a PDF reader, this software is ideal for reading books and taking notes on specific chapters or sections. The annotation tools are quite extensive and they’re easy to apply to the document. The tool is especially great for tagging long text notes to a specific location of the PDF document you are working on. The only problem is that the interface is a little cluttered so you may take time in finding the right tool.


Good PDF reader with extensive mark-up tools, especially good for text annotations (commenting, reviewing)

8. Xodo PDF Reader

Xodo is available on the Microsoft Store and is a free PDF reader. You can make minor edits but it is not a proper PDF editor like PDFelement or Adobe Acrobat DC, where text and other elements can be added, removed, or modified. You can cover existing text with a blank box and then add some text on top of that. However, the annotation tools are quite impressive and you’ll find everything you need to take notes, add comments, highlight text, mark content sections, and so on.


Completely free with no ads or in-app purchases, good selection of annotation tools.

9. HowNet Research: Excellent For Research Students As A Robust PDF Reader And Markup Tool

Previously called E-Study, this is a must-have tool for college students and researchers. The annotation tools are great to use and you’ll find everything you need. The software even has attractive features like cloud syncing, organizing PDFs, and even OCR on the desktop version. This is especially useful for scanned PDFs where you cannot select and copy text portions.


Ideal for students, teachers, and researchers, partial OCR, great for annotations.

10. Drawboard PDF

And finally, one of the best PDF annotation tools for touchscreen devices that support a stylus. It offers some unique features such as markup history, adding notes to your annotations, a favorite tool customizable menu bar, and the genuine feeling of writing on paper, according to the website. The tool is one of the most popular productivity utilities on the Microsoft Store and is available as free as well as Pro versions.


Ideal for touch-based interfaces like Surface tablets and convertible 2-in-1 notebooks. Great for adding annotations and notes with a stylus.

These are the 10 best annotation tools for PDF whether you’re a novice or an expert PDF user. As you have seen, some of them have advanced annotation capabilities while others offer just basic note-taking tools. Try them and see which one works best for the kind of tasks that you deal with on a daily basis.

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