How to Annotate a PDF – The Ultimate Guide & 5 Great Software Solutions

how to annotate a pdf

“How do I annotate a PDF document?” If you ever have tried to annotate a PDF, you have probably discovered just how painstaking such a simple process can be. With an estimated 2.5 trillion PDFs in the world, there must be an easy way to work with such a commonly used file format. Luckily, there is – and most people don’t even know how much time, energy and even money they can save when working with the right PDF annotation tools.

Why and When Are Annotations in a PDF File Useful? 

How can you annotate a PDF? Most readers of this article have needed to annotate text inside a PDF, only to find out that PDFs offer very limited capabilities when it comes to text editing features.

The PDF format was created by Adobe in the early 1990s as a way to replace large document files that were painful to share. At this time, computing power was much more limited than it is today. 

PDFs were able to combine all graphic design elements into one file while keeping the document size as small as possible. Even though this advantage is outdated in today’s day and age, there are many other reasons why PDFs remain popular:

  • Portability: No matter if you use Windows 10, a Mac, an Android or an iOS device – PDFs work across all systems.
  • Security: PDFs contain many security features, such as deactivating printing abilities or disabling the copy/paste function. Furthermore, you can protect your PDF with a password.
  • Usability: PDFs contain fillable fields which allow customers to add information such as name and address without changing any other content. You can even add electronic signatures without printing the document.

Even though these features are still useful by today’s standards, the lack of annotative PDF functions can make it difficult to collaborate. However, sometimes, there is no way around it. As we could see above, there are many reasons why your clients or even copywriters may want to send you a PDF file that incorporates these security and usability features from the get-go.

For instance, if you prepare a contract, you usually send it out via a PDF, so that you can collect signatures without worrying that anything else has been changed. But what if you receive and need to annotate PDF files, for instance, to strike through some words or just to leave a general comment? What if you need to highlight and underline text sections or even copy text from the document?

There must be a way to annotate PDF files without making screenshots or using other half-baked solutions. This is exactly where PDF annotation software comes into play. With the tools provided by a capable software solution, you can annotate PDF files, solve the above-mentioned problems and add much more valuable collaboration features to your PDF file workflow.

The advantages of a PDF annotation software are outlined in the following section.

How to Annotate a PDF: Important Features of PDF Annotation Software

What are the advantages that capable PDF annotation software should offer?

To make it clear, since PDFs are fixed documents, we cannot expect fully-fledged text editing features such as those offered by Microsoft Word, Google Docs or Apple’s Pages. But, if we want to maintain some of the above-mentioned security features in a contract or scientific paper, it is often necessary to work with a PDF file.

When doing so, we can expect to be able to use annotated PDF features to facilitate the collaboration process between the PDF creator and all reviewers involved. Otherwise, valuable working hours are lost on both the creator and reviewer side, which would turn simple PDF annotations into a costly project for your company.

Therefore, the software must enable the reviewer to highlight sections and to add comments, at the very least. Generally speaking, PDF annotation software should contain the following basic features:

  • Highlight text section: To draw the attention to a specific section, you should be able to highlight text with different colors.  
  • Strikethrough text: You need to be able to strike through text in order to highlight unnecessary parts of a copywriting project or a contract.
  • Copy text: To make text changes, it is necessary to be able to copy/paste the PDF text.
  • Leave a comment: Besides marking required changes, you also need to be able to easily leave commented annotations to explain in more detail what needs to be changed.
  • Add hand drawings and shapes: Being able to make drawings and add arrows, lines or shapes gives you the possibility to give even clearer feedback.  
Features of PDF Annotation Software

Some PDF annotation tools also offer more customized content review solutions and allow you to freely draw shapes. While a usual PDF reader is already incapable of providing basic annotations, fully-fledged PDF annotation software can do much more, as we will find out in the next section.

Example: How to Annotate a PDF with Filestage

In the following example, we demonstrate how a powerful PDF and annotation tool can help your company save time and create high-quality documents.

A common scenario usually consists of content creators who are responsible for uploading the first PDF draft at a predetermined deadline. The review team usually consists of three or more people, all of whom need to be able to add annotations.

If you do not use PDF annotation software, things can become messy very quickly: Some reviewers may take screenshots and add them to a PowerPoint file, while others may explain everything in a very long text message.

Furthermore, if you do not receive all feedback in one centralized place, it can take a lot of time to collect, summarize and compare the feedback from different reviewers. You might receive the same feedback twice or get contradictory suggestions that require further discussions between the reviewers.

Review and approval software such as Filestage can bring order to your PDF annotation process. With Filestage, content creators can upload the PDF file on a centralized platform where it is automatically shared with the review team.

Then, reviewers can highlight sections, strike through text, copy and paste, leave comments and make suggestions for revisions. All users can leave a general or context-based comment by clicking in the file. Team members and project collaborators can even decide if every reviewer or only certain team members can see their comments. Additionally, you can make freehand drawings, add squares, arrows and lines in different colors to customize your feedback.

how to highlight sections of a PDF

But this is just where Filestage starts – the review and approval software shines with its document collaboration tools. As a cloud-based platform, Filestage makes all comments and annotations instantly visible by the team. This allows you to collaborate and discuss feedback in real time.

review and approval software for pdf

Furthermore, Filestage allows you to easily search for comments and sort them by the newest, oldest or by page number inside the text. You can also use an automatically created to-do list and even export a review report that includes all comments added to the file.


Finally, Filestage includes a huge variety of additional features, such as advanced search functions, page layout options and different document views. By using Filestage, each of your team members will enjoy a more efficient review and approval process for PDF documents, giving them more time to concentrate on the things that matter most.

Overview of the 5 Best PDF Annotation Software 

You might wonder: “What is the best way to annotate a PDF?” Now that you know how good PDF annotation software can streamline annotations, we review five of the best PDF document annotation software solutions on the market.   

Filestage – PDF review and approval tools

Filestage – PDF review and approval tools

Filestage is much more than just a PDF annotation software. Filestage allows you to streamline the content approval process by making it easy to annotate PDFs, images, videos and more within a single, cloud-based platform. 

With Filestage, your colleagues and external partners can utilize many annotation features to easily leave precise feedback on PDF files. Furthermore, the platform is user-friendly and has an intuitive interface that enables reviewers to get started in minutes. Plus, you can invite as many reviewers as needed, since they can leave comments without creating an account.  

Adobe Acrobat Reader – free PDF reader and annotation tool

Adobe Acrobat Reader – free PDF reader and annotation tool

The Adobe Acrobat Reader basic version allows you to use annotation tools to annotate, comment, print and sign PDFs. Acrobat Pro DC further lets you create PDFs, export PDFs to Word or Excel files, add passwords and signatures and track responses in real time. 

With Adobe Acrobat Reader, it is easy to annotate and share documents with multiple reviewers through a single online PDF file. For more free design sources, you can also check out our blog entry Free story canvas template.

Drawboard – 2 collaboration and markup tools

Drawboard – 2 collaboration and markup tools

Drawboard is a practical PDF markup and collaboration software that consists of two annotation tools. With Drawboard PDF, you get drawing and annotative features for PDFs. The program can even feel just like drawing with pen and paper. 

Text review, shape insertion, sticky notes, bookmarks and many more annotation and markup tools help you annotate and customize each PDF. 

With Drawboard Projects, formerly known as Bullclip, you get all of the collaboration features needed to work efficiently in small or large teams. You can further collaborate on every document, perform live markups and discuss changes to be made. 

iAnnotate PDF – for seamless PDF workflows

iAnnotate PDF – for seamless PDF workflows

iAnnotate by branchfire offers versatile annotate PDF tools that create seamless and secure PDF workflows. Thanks to iAnnotate’s security features, reviewers can include critical business insights in PDF files. iAnnotate is as intuitive as sticky notes; you can add a drawing or personal note, annotate sections and share feedback with other team members on your iPhone or iPad. 

The iAnnotation document review and approval workflow follows the PDF standard, so that other full-featured PDF applications can read annotations created in iAnnotate. Furthermore, iAnnotate can be seamlessly integrated with Office 365, Intune and many more applications.

Notability – PDF note-taking and sketching tool

Notability – PDF note-taking and sketching tool

If you are wondering, “Can I write notes on a PDF?”, Notability has the answer. Notability is a  PDF annotation software that is optimized for Apple devices. It allows you to markup photos, annotate PDFs and to create original content that can be easily shared inside and outside of your organization. 

With Notability, you can combine handwriting, photos and typed text together in a single note as well as make use of a wider range of tools to draw and highlight additional details. You can continue to scale, rotate or to recolor your note, zoom in on the specifics, or even combine sketches and outlines. 

Additionally, with Notability, your notes, review and PDF documents are all in one place, so that you keep track of all work in progress.


PDF documents are here to stay – as we have seen, there are still a lot of unique use cases when PDF files are needed. Therefore, we are dependent on reliable tools to annotate PDFs.

In order to tackle your PDF projects more efficiently and to reduce costs while increasing the quality and consistency of your files, there is no way around using a capable PDF annotation as well as review and document approval software

We hope we have given you valuable insights as to how to streamline your PDF workflow and unleash the full creative potential of your content creation and review teams.

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