13 Best Free PDF Annotator Software

Here are 13 best free PDF annotator software for Windows. These software let you annotate PDF files for free. Most of them are rich with features and annotation tools like highlighter, notes, text box, underline, shapes, stamps, and signature. Few of these PDF annotators also carry annotations like sticky notes, from other PDF annotators. You can also use some of these software to share your annotated PDF directly via email, Evernote, Dropbox, or Facebook.

Annotate means to add notes as an explanation, or comment. Sometimes we need to annotate PDF files to explain its content clearly to it’s viewers. This explanation can be carried out with the help of highlights, texts, or other geometrical shapes. All of these basic tools must be available in an ideal PDF annotator.

My Favorite PDF Annotator:

Adobe Acrobat Reader is my favorite, and the best PDF Annotator, because it has a set of most advanced and best annotating tools. The User Interface is flawless, and user friendly. All the annotation tools are free to use, and this software works both as a PDF viewer and editor (premium feature).

You can also take a look at the list of Free Online PDF Editors, Free PDF Editor Software for Windows, and Best Free Online DOC To PDF Converters.

Here is a list of 13 Best Free PDF Annotator Software For Windows: 

Adobe Acrobat Reader

Adobe Acrobat Reader is a pioneer among PDF readers. You can easily view PDF files and add annotations to them with the help of this free PDF viewer. The available annotation tools on this PDF viewer are: Sticky notes, Text highlighter, text under liner, add note to text, text strike through, text box, draw free form,  stamp,  attach multimedia files, and geometric shapes. You can also add signatures as text, drawn signature, or an image of your signature. Go through the comments to find out all the added annotations. You can also filter or search for any particular annotation. After adding annotations, save the PDF on your PC. You can also directly print or share the annotated PDF from this software.

Foxit Reader

Foxit Reader is a free PDF reader and a PDF annotator.  This PDF reader includes annotation tools like: typewriter, note, highlighter, strikeout, underline, bookmark, links, digital signature, and multimedia attachment. You can also open and view a PDF with annotations on it. Add a text replacement note, freehand drawing, text box, shapes, or highlight areas with the help of this PDF viewer. View comments to filter out a specific annotation. Import, export, and print directly via this PDF viewer. It has various other PDF tools to it, such as digital stamp, scale, area highlighter, text reader, auto scroll, and digital protection. Share PDF directly via email, Evernote, and Facebook.

PDF-XChange Viewer

PDF-XChange Viewer is another PDF annotation software, available for free. This software includes basic PDF markup and comment tools. Apart from basic tools like: highlighter, sticky notes, stamps, text box, type writer, strikeout, under line, and free hand pencil, it has other advanced annotation tools as well. These tools include measuring tools, link tools, arrow and shape tools, call-out and snapshot tools.  It can also load annotations from other PDF annotators as well. Bookmark, and add/view annotation comments easily on this freeware. This is one of the lightest PDF annotators available. Features like signature, and adding attachments are available in the pro version.

Nitro Reader

You can perform PDF annotation for free on Nitro Reader. This is another PDF viewer with standard annotation tools. It has following annotation tools: Text select, notes, text highlight, strikeout, underline, type text, and signature. You can view already added annotation comments, attachments, and bookmarks on a PDF. You can also convert the PDF to text, or extract images from PDF with the help of this software.

Expert PDF Viewer

Expert PDF Viewer lets you view and annotate PDF documents for free. It has a standard set of annotation tools which include: sticky notes, highlighter, strike-out, underline, pencil, file attachments, stamps, signature, and text box. It lets you view/add bookmarks, and comments to a PDF without any problem. Review the annotations with the help of review tool. This PDF Annotation freeware also lets you view PDF pages in different layout fashions.

Soda PDF 3D Reader

Soda PDF 3D Reader gives you a 3D environment to read PDF files. You can also annotate PDF documents on this freeware. View/add notes to PDF files, use markup tools such as highlight, underline, and strike-through. These markup tools can be used in any desired colors, for example you can highlight different lines/words in different colors. It lets you view annotations made by other PDF annotators as well. View and add attachments and comments to the PDF. You can also view signatures on this PDF viewer. It lets you take a snapshot of a selected area of PDF files, and copy it to clipboard.

Mendeley

Mendeley is a PDF management tool, which also works as a PDF annotator, and PDF viewer. It has the capability to carry over limited annotations from other PDF annotation tools. Select text or area, highlight text or rectangle, and add notes. This PDF viewer has only limited, and elementary markup tools for annotations. You can only view highlighted, crossed out, underlined, or drawn projections from previous annotations. You can not view previous sticky notes. This tool can only be used for basic annotations.
Share your document via email easily on this freeware.

Qiqqa

Qiqqa is an elementary PDF viewer which can be used for free. It lets you View and annotate PDF documents with basic annotation tools. These tools include: highlighter, draw, add and select text. You can also add annotation comments with this software. This is a  fairly good PDF annotator, and an even better PDF viewer. There’s more to this PDF viewer but those functions are available only for premium subscribers.

Gaaiho Reader

Gaaiho Reader is an efficient PDF viewer and PDF annotator. The annotation tools available are standard, and it supports sticky notes. Other tools are note, type writer,text box, highlight, cross out, underline, signature, stamps, attachments, bookmark and comments. Other extra features are available on this software as well. You can apply encryption to a PDF document, find and locate any word on the file. Documents can be shared directly via email, or can be sent to Evernote or Dropbox. It also lets you view PDF in different views.

Microsoft OneNote

Microsoft OneNote is a prominent software to annotate PDF files. You cannot directly open a PDF file in OneNote, but you can open it as an attachment. Create a notebook, and a note under it, then attach the PDF file you want to annotate and share. Once you have attached the PDF, you will be able to view it on the UI. You can view annotations on the loaded PDF if there are any. To annotate, go to the Draw tab where you will find different highlighting tools. These highlighting tools are available in different size, color, and opacity levels. You will also find different shapes, like arrow, direction, circle, square, etc. Their colors can be changed as well. Select an area and type on it. The eraser function lets you undo any annotation easily. Save the PDF and share it with others.

PDFedit

PDFedit is an open source PDF editor where you can annotate and edit PDF files. When you open a PDF document, you can go to the Annotations tab to add different annotations, like: Insert comments, links, and highlight. Apart from these functions, you can also add Text and Images to your PDF file. The options available also let you change the color of highlighter and text. This PDF annotator lets you change, delete, snapshot, and extract images. You can also Debug a PDF file with the help of this PDF editor.

Paint.net

Paint.net is a prominent image editor. With the help of plugins, this image editor can be used as a PDF annotator. These plugins let you open and save PDF files in Paint.net. Once you open a PDF file, you can annotate with the help of text, paint, and shape tools. Different shapes are available to help you to make a desired shape to enter text, or highlight an area. Download and install the plugins from the mentioned page, and start annotating PDF files on Paint.net. Both Paint.net, and the plugins are available for free.

Notable PDF

Notable PDF is a freemium Google Chrome Extension to view and annotate PDF files. This PDF annotator is capable of carrying out basic annotations like highlighting, underline, strikeout, adding text, etc. You can view and annotate PDF files easily on Google Chrome online/offline. You can also save the PDF file to your PC or upload to Google Drive via Notable. This extension also lets you add user comments to the PDF file. This is an extremely light application, and really easy to use. You can even change the colors of all the annotations. This PDF annotator extension for Chrome also lets you view your PDF file in different views. Sign up for premium account and you can access features like sign, split,and merge documents.