13 Best Annotation Tools to Try

Are you looking to markup files and documents? Wondering what are the best annotation tools to use?

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FACT: Collaborating on content gets so messy sometimes. Great ideas get lost in endless email chains. Feedback and comments often lack context, making them impossible to act on. And even when you’re trying to explain them better, there’s still something missing. 

But it all changes when you can add comments directly on the piece of content. When you can annotate an image or video, leave comments beside a paragraph of text, mark elements on web pages that need changing, etc.

Enter annotation tools, software that allows content creators to do just that. 

In this guide, you’ll discover 13 of the best annotation tools today and learn how they can improve your feedback and approval workflows

So, let’s get to it. 

What Exactly is Annotation Software?

The term – annotation software – refers to tools that allow you to mark and draw on other files – images, videos, text files, PDFs, and more – to provide precise comments and instructions. 

Different annotation tools use different types of annotation, from simple text comments and notes to allowing users to color-code and label elements of a document, add signatures, and more. 

When to use the annotation software?

Organizations use annotation tools in a variety of situations. Here are just some examples:

  • Many companies implement annotation software to comment and provide contextual feedback on content assets across the entire content production process. Such platforms help team members provide more meaningful feedback that can be acted on quickly. 
  • Annotation tools help teachers highlight important passages in text files submitted by students. 
  • Many organizations use annotations to add suggestions for improvements to various assets they work on and data and other file formats. 
  • Teachers and educational institutions often use collaborative annotation to help students develop their reading, writing, and critical thinking skills.

Overall, annotation tools are ideal when you need to provide meaningful feedback and leave comments directly on a file or a data set. 

But there’s a problem, right? Search for annotation tools in Google, and you’re immediately overwhelmed by the number of options available. 

How do you decide which software to use?

Here are some suggestions for how to evaluate the tool. And further down in this guide, you can review 13 of the best annotation tools today to evaluate for your annotation process.

What to Consider When Selecting an Annotation Tool

Most annotation tools focus on specific uses or use cases. Some help with annotating files. For others, annotation features are only part of a larger project management platform that helps companies deliver content more efficiently. 

For that reason alone, you should evaluate each tool against these three criteria:

#1. Functionality

Consider what you will be using the tool for. Do you need it just to annotate files? Or does your team struggle with creating content efficiently? Some annotation tools will help you improve feedback; others will also provide features to scale content production. 

Each of the tools on our list has its distinct set of features. So, as the first thing, check whether the software’s key features match what you’ll be using it for. 

#2. Annotation capabilities

Secondly, different tools focus on different file formats. Most allow marking up text or PDFs. Many offer image annotation options, and some also allow you to annotate videos or databases. 

When evaluating annotation tools, also pay attention to what file types the tool works with. 

#3. Efficiency

Annotating files seems simple to do. But from the software point of view, it’s a complex process that requires adding more information to an existing file. Some tools handle this better than others. They work slower on certain file types and may even struggle to process more complex assets. 

So, if you find tools you like, take them for a trial. See how well the tool performs tasks and if you’re happy with the speed and efficiency.

With all that in mind, here are the best annotation tools to consider.

13 Best Annotation Tools for 2023


CELUM (disclaimer: this is our tool) is one of the most advanced online proofing tools, with equally advanced annotation features. 

Because of that, CELUM offers an incredible range of annotation capabilities:

  • The ability to share precise and actionable feedback directly on files
  • Annotations on videos, images, text, PDFs, and other common file formats. 
  • CELUM gives you access to a complete revisions history to compare different versions of files and monitor how projects evolve. 
  • Mentions to notify other team members about new annotations.
  • Email notifications and triggers to keep everyone informed, and more. 

But CELUM offers a whole range of other capabilities to help your team create content faster and at a scale. 

  • Online proofing that makes review and approval processes a breeze.
  • Content hub to keep all assets in one place, easy for everyone to find.
  • Project management with advanced Kanban boards, tasks, and project templates. 
  • Content workflows will help you streamline creative processes.
  • Finally, a whole range of integrations will make CELUM an amazing part of your creative stack.

Pricing: CELUM offers a free plan for small teams of up to 10 people. Bigger teams can avail of paid plans with additional functionality starting at €14.90/per month. 

Looking for an annotation tool?

Want to see how CELUM can help your brand improve annotations and scale content production?

#2. Filestage

Filestage is another online proofing tool that offers annotation tools as part of its toolstack. With Filestage, teams can add feedback on almost all common file formats and add annotations in context. 

However, Filestage’s main focus is on centralizing review and approval processes and allowing teams to save time and just get on with their creative work. 

Pricing: Filestage pricing starts at €12 per user per month. Team plans start at €24 per month per seat.

#3. Annotate

Annotate is a document collaboration tool that helps teams take their documents from the first draft to a completed asset. Annotate focuses on allowing teams to create documents on time, and for that reason, the tool focuses on selected file formats only – text files, PDFs, etc. 

One of the unique features of Annotate is the ability to store documents on a private cloud or even on your servers. 

Pricing: Annotate offers a limited free plan. The company doesn’t disclose paid plans on the site, and you need to contact them directly for those. 

#4. Doccano

Doccano is open-source software that incorporates machine learning to expand traditional annotation features. With Doccano, you can perform sentiment analysis of your text, text classification, use data annotation tools, and even use sequence to sequence learning to create training data models. 

Pricing: Doccano is a free tool.

#5. Ink2Go

Unlike other apps on our list, Ink2Go is desktop software. This means that you need to install it on your computer. But it also means that you can use it on top of almost any other software you’re using, even on video. Ink2Go then lets you save those annotations as images to share further. 

Pricing: Ink2Go requires a one-time license of $19.90.

#6. PDF Annotator

As the name suggests, this annotation tool works with PDFs only. But it offers a whole range of features to annotate this file format. You can comment on any PDF, edit it, add corrections and highlights, and even add photos and drawings. You can then save your annotations in the original file to share them with your team and restore the original document without comments easily. 

Pricing: PDF Annotator is also a desktop tool, and a single license costs €69.95. 

#7. Markup Hero

MarkupHero is a screenshot and annotation tool that aims to speed up your content creation workflow. With MarkupHero, you can communicate with the team better through the screenshot app and image and PDF uploader. You can also annotate an image, PDF, or website using various annotation features. 

Pricing: MarkupHero offers a free plan. It also offers a paid plan at $4/mo per user.

#8. Zoho Annotator

Zoho Annotator is a screen capture and annotation browser plugin that helps to add contextual comments on web pages without leaving your browser. It’s an ideal tool for teams that regularly review website designs and need to provide comments and instructions to other stakeholders. 

With Zoho Annotator, you start by taking a snapshot of a website. Then, you use annotation tools to provide feedback, highlight potential errors or mistakes, etc. You can also blur or smudge confidential data before sharing the image with your comments.

Pricing: Zoho Annotator is a free Chrome extension.

#9. ClickUp

ClickUp is a robust project management platform bringing together various capabilities and tools to allow teams to do all of their work in one place. With ClickUp, you can plan projects, collaborate on documents, chat and exchange ideas, and more. 

But ClickUp also features an annotation tool that allows you to markup PDFs and images directly from the tool. 

Pricing: ClickUp offers a free plan. Paid plans start at $9 per month per user.

#10. GoVisually

GoVisually is an approval and review software helping companies move away from offering feedback on content via email. Instead, the company offers a whole range of proofing solutions to provide visual feedback and annotations directly on design files, images, PDFs and video content.

With GoVisually, you can upload your files to the platform, add feedback and mark them up before sharing them further with other stakeholders. 

Pricing: GoVisually offers two pricing plans. The first one costs $25 per month and is ideal for freelancers. The Team plan starts at $60 a month for 5 users. 

#11. Diigo

Diigo is another Chrome extension that allows you to annotate and markup online PDFs and webpages directly from the browser. With Diigo, you can add sticky notes, highlight content sections, place tags, outline documents, and more. 

On top of that, Diigo lets you build a list of bookmarks, tag your collected web pages, and share your research with colleagues. 

Pricing: Diigo offers a limited free plan. Paid plans start at $40 per year. 

#12. Superannotate

Superannotate is quite a unique annotation tool on our list. It does provide a whole range of capabilities to annotate data. However, its focus is on annotating and managing ground truth for artificial intelligence. 

With SuperAnnotate, you can create high-quality training datasets for object detection, instance, semantic segmentation, keypoint annotation, data labeling, or video tracking. 

Pricing: SuperAnnotate does not make its pricing public.

#13. RedPen

RedPen is all about making content collaboration as easy and fast as possible. The tool allows you to upload designs, add comments and annotations, and ask colleagues for feedback. You can also organize your work into projects to ensure that all assets are in one place and keep track of each file revision. 

Pricing: RedPen offers pricing plans based on the number of projects. Plans start at $20/mo for 5 projects.

And there you have it…

Thirteen of the best annotation tools to capture feedback in context, and speed up team collaboration.

All that’s left for you is to review each of them and pick the one that suits your needs the most. 

Good luck!

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