6 Best PDF Annotation Apps for iPad 2025 [Free Ones Included]
Introduction:
The Apple Pencil makes writing on an iPad feel just like writing on paper. While the built-in Notes app works wonders, it’s limited for working with PDFs. If you want to annotate a PDF on an iPad, a good PDF annotator is a must. No matter what you do, using the right tool makes a significant difference. If you need a recommendation for the best PDF annotation apps for iPad, keep reading. We’ve picked six of the best apps, including a few free choices.

#1. SwifDoo PDF for iPad

SwifDoo PDF for iPad offers a lightweight yet powerful interface. It is one of the best apps to annotate PDFs on an iPad. You get features such as highlighting, underlining, strikethrough, and adding sticky notes. You can even do freehand drawing, add shapes/text boxes, and customize stamps.

Install SwifDoo PDF for iPad App

It is indeed the best PDF annotation app for iPad as it supports reflowed text for better readability. When you import or drop in PDFs, you can annotate freely. After saving the changes, any emailed or shared version retains all your comments and markups intact.

Pros

  • Best PDF markup app, viewer, annotator, and converter app for iPad.
  • Access, manage, and collaborate on PDF documents on the go.
  • Supports reflowed text for better readability. Offers full-text search within PDFs.
  • Access to a swift annotations panel for managing markups.

Cons

  • The free version has basic and limited functionality.

#2. Adobe Reader

The Adobe Reader iPad app is also among the best PDF annotation apps for iPad to use for free. It helps tweak and modify the PDF files stored locally on devices. Additionally, it allows users to access PDF files from cloud-based platforms. The best PDF app for iPad will enable you to annotate a PDF by adding sticky notes, shapes, highlighters, and even arrows. Adobe Reader also allows for free-form note-taking on pages and text search of your notes.

Pros

  • Best PDF reader for iPad and iPhone with various PDF annotation tools.
  • Works seamlessly with scanned PDF files and advanced viewing tools.
  • Transfer files via cloud services like iCloud and Google Drive.
  • Enables users to access a host of other features through in-app purchases.

Cons

  • Steep learning curve for new users.
  • Slowdowns, crashes, and lags when handling large PDFs.
  • Downsampling or distortion of handwritten annotations, especially with the Apple Pencil.
  • Lacks handy annotation features such as the lasso tool and reflow.

#3. Notability

Notability excels as the best PDF annotation app for iPad due to its highly intuitive interface. Due to its ease of use, you will be quite fond of using Notability for iPad PDF annotation. Additionally, the free version of Notability includes various AI-based functionalities. The app facilitates handwriting, sketching, and the integration of audio and photos into PDF documents. The app offers options to select the paper color, style, and font size for reading PDF files as desired.

Pros

  • Share and sync documents through cloud services.
  • Combines document and notes management capabilities.
  • Merge various PDF documents into one while retaining formatting.
  • Bookmark, highlight text in multiple colors, and much more.

Cons

  • Lacks landscape pages and auto shapes.
  • Cannot delete multiple pages quickly.
  • Generates comparatively larger PDF files.
  • A large margin is added around documents when importing PDFs.

#4. LiquidText

When you have to work with projects, research papers, or novels, LiquidText does the job for you. LiquidText might be the best app for PDF annotation on iPad if you work with large files. Moving beyond paper, LiquidText helps organize documents with lightning speed. To know how to annotate a PDF on iPad using this app, import your PDF, select the text, and then drag it into the workspace item for notes and connections.

You can even use the highlighter and pen tools of the best PDF annotation app for iPad to mark the document directly.

Pros

  • Add detailed comments, sticky notes, and text boxes.
  • Tag and organize documents with deep annotations.
  • Streamlines the process of collecting, connecting, and organizing information from various documents.
  • Transforms static PDFs into interactive documents from multiple sources at once.

Cons

  • Requires an expensive subscription plan to unlock full functionality.
  • The app struggles with huge files, sometimes leading to crashes, slow loading times, or freezing.
  • Poor synchronization across different devices, even within the Apple ecosystem.
  • Handwritten notes are not convertible to searchable text.

#5. PDF Viewer by Nutrient

When we talk about the best free PDF annotator for iPad, PDF Viewer deserves a special mention. Its simple and clean user interface makes it easy to use powerful annotation tools for users of all skill levels. You can zoom, share, and browse through annotations effortlessly. PDF Viewer by Nutrient is the best iPad app for PDF annotation, making it easy to rearrange, delete, and insert blank pages within a PDF.

Besides annotation, PDF Viewer allows you to fill forms, sign, edit, and redact content from PDF files.

Pros

  • Highlight and markup texts while reviewing a document.
  • Add notes, text, or drawings directly on the PDF.
  • Add images or audio and reply to notes.
  • Create, edit, sign, add a password, and share documents.

Cons

  • Many advanced features are locked behind a pricey subscription model.
  • Inconsistent updates with changed UI and slowdowns.
  • Occasional bugs and freezes on older devices when handling large documents.
  • Lacks a lasso and a snapshot tool for annotation.

#6. iAnnotate 4

Lastly, iAnnotate 4 can also be the best software to annotate a PDF on an iPad. It allows you to take notes on a PDF, much like writing on paper. Once you have made the annotations, you can drag and drop them anywhere in the document you like. Wonder what other features make it stand among the best PDF annotation apps for iPad? Well, iAnnotate 4 lets you strike out, add a signature, and make sound clips to embed within the PDF.

Pros

  • Annotates PDFs, Office files, and web captures.
  • Suitable for standard annotations like highlighting, underlining, and strikethrough.
  • Add text comments, shapes, and sticky notes.
  • Supports adding new images and stamps.

Cons

  • Does not work on devices other than iOS.
  • Offers only basic annotation features.
  • Cannot add stickers, new texts, or edit text/images.
  • Neither merges/splits PDF files nor integrates ChatGPT to analyze/chat with documents.

Final Wrap Up

Here, we conclude our review of the 6 best PDF annotators available on iPad. As you can see, there are many options to help you highlight, draw, comment, and sign with ease. If you don't want to pay any subscription fee, try free apps like PDF Viewer and Adobe Reader—they work well. Tools like SwifDoo PDF for iPad, Notability, and iAnnotate 4 are also great. Additionally, some best PDF document annotators also come with Windows and Mac versions for cross-platform use.