Markup

Annotate, collaborate, and review with precision

Bring real-time feedback and structured discussions into your document workflow. Nutrient lets users mark up PDFs with highlights, comments, replies, and custom annotations — all within your app, on any platform.

What do you want to do with documents?

Add rich annotations to documents

Let users highlight text, draw shapes, add stamps, and leave freeform notes — all with precise control over style and behavior.

Enable collaborative review workflows

Support threaded comments, replies, and resolution states to capture feedback directly on the content, without switching tools.

Sync markup across users in real time

Use live collaboration to keep annotations, comments, and replies in sync — whether users are reviewing together or asynchronously.

Control markup access and visibility

Set fine-grained permissions for who can view, edit, or comment — down to individual users, groups, or roles.

How we help


ANNOTATIONS

Add highlights, shapes, and more — directly on the document

Give users tools to mark up PDFs with highlights, arrows, freehand ink, stamps, and custom annotations.

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Real-time, in-document markup

Users can draw, comment, and highlight directly on the page — no need to export or flatten.


Support for all standard annotation types

Includes highlights, underlines, strikeouts, shapes, free text, stamps, and more.


Cross-platform rendering

Ensure annotations display identically across web, mobile, and desktop.


Custom annotation styles

Control colors, opacity, and behavior to fit your app’s design.

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COMMENTS AND REPLIES

Capture discussion next to the content

Let teams have structured conversations inside documents — attached to highlights, shapes, or any other markup.

Threaded replies

Turn a single comment into a full discussion without clutter.


Comment on any annotation

Link feedback to highlights, drawings, stamps, or shapes.


Resolve, reopen, or delete

Manage comment threads throughout your workflow.


Custom author tagging

Track exactly who said what, and when.

Markup instant collaboration

INSTANT COLLABORATION

See every annotation, comment, and reply update in real time

Instant keeps users in sync, whether they’re marking up a PDF together or reviewing feedback in their own time.

Live collaboration

See changes as they happen — no refresh or save required.


Conflict-free editing

Multiple users can comment or annotate without overwriting each other.


Real-time syncing across devices

Annotations appear instantly for every viewer, on any platform.


Granular access control

Control who can view, edit, or comment on shared documents.


Supported on your platform




Prefer a cloud deployment?

Nutrient’s Document Web Services (DWS) platform offers cloud-native APIs that support every stage of the document lifecycle — from rendering a single PDF in the browser, to high-volume processing and automation.

DWS Processor API

Handle advanced, headless document workflows from the cloud — generate, convert, extract, add watermarks, and more with a processing API built for scale.


DWS Viewer API

Deliver rich, interactive document experiences directly in the browser — render PDFs, annotate, fill forms, and collect signatures with a cloud-hosted viewer API.


Frequently asked questions

What annotation tools are available in Nutrient’s SDK?

Nutrient provides a full suite of markup tools — including text highlights, ink and shape annotations, comments, stamps, and signatures. You can access them through a customizable toolbar, configure behaviors like noZoom, and manage annotations in bulk using the API.

How does real-time collaboration work for markup and comments?

Multiple users can annotate the same document simultaneously with instant updates. Changes sync in real time and integrate with version history, enabling seamless collaboration for review cycles, approvals, and shared editing.

Can I use Nutrient’s SDK for document review?

Yes. Nutrient’s SDK is designed for document review workflows. It supports threaded comments, resolution states, and real-time collaboration, making it ideal for collaborative document review and approval processes.

What measurement tools are included for technical use cases?

The SDK includes tools for measuring distance, angle, and area — complete with scale calibration and unit conversion. Ideal for architecture, construction, engineering, and other precision workflows.

Can annotations be secured or restricted with permissions?

Yes. You can apply role-based permissions to control who can view, add, or edit annotations. Markup can also be secured with digital signatures or flattened to prevent modification.

Can I edit metadata or track document context?

The SDK supports editing and managing XMP metadata inside PDFs, allowing teams to preserve document context, categorization, and versioning alongside markup.

Which platforms and frameworks are supported?

Nutrient’s markup tools work across web, desktop, and mobile environments — with official support for JavaScript, iOS, Android, React Native, Flutter, and MAUI.

Does the SDK support offline markup workflows?

Yes. Annotations can be stored as XFDF or Instant JSON for offline use, and synced back to the server when a connection is available. Server-connected environments enable real-time syncing across users.

Can annotations be exported, imported, or reused across documents?

Absolutely. Annotations can be serialized to XFDF or Instant JSON formats for storage, import, or reuse. You can apply saved markup to new documents or across different sessions with minimal overhead.


Insights from our team

EXPLORE BLOG

PROVEN AT SCALE

Trusted by the brands that move the world


Replaced paper and email with Nutrient Workflow to automate multilevel approvals across six Latin American offices, processing 236 asset requests.


Renders multipage PDFs and signature tags with Nutrient, keeping 200 million users in 188 countries moving at the speed of eSignature.


Empowers 34,000 pilots to view, annotate, and sign 90‑page flight releases on iPad using Nutrient iOS SDK, saving minutes — and money — on every flight.


PDF markup tool

What is a PDF markup tool?

A PDF markup tool is a software application that enables users to annotate, comment, and highlight content within PDF documents. Nutrient’s PDF markup SDK offers a comprehensive suite of annotation features, including real-time collaboration, measurement tools, and metadata management, making document review and collaboration more efficient.

  • Add comments, highlights, and annotations in multiple formats.
  • Use measurement tools to calculate distance, area, and perimeter.
  • Enable real-time collaboration with simultaneous document markup.
  • Customize annotation styles to match branding and user preferences.
  • Ensure document security with digital signatures and access controls.
How to choose the right PDF markup tool?

When choosing a PDF markup tool, it’s essential to consider factors such as collaboration features, measurement capabilities, and API flexibility. Here’s what to focus on:

  • Annotation variety — Ensure support for text highlights, comments, shapes, and rich text annotations.
  • Measurement accuracy — Look for built-in tools to measure distance, area, and perimeter.
  • Real-time collaboration — Opt for tools that allow multiple users to annotate and review documents simultaneously.
  • Metadata management — Ensure support for XMP metadata to maintain document integrity.
  • Security and permissions — Prioritize solutions that provide access control and secure document handling.
What are the best solutions to solve my PDF markup problem?

To enhance document collaboration and annotation, you need a solution that balances usability, collaboration, and customization. Nutrient’s PDF markup SDK excels in this area. It offers comprehensive markup tools, real-time collaboration, and secure document management.

What are the benefits of using Nutrient’s PDF markup tool?

Nutrient (formerly PSPDFKit) improves document review workflows by providing feature-rich annotation tools, real-time collaboration, and secure document handling.

  • Comprehensive annotation options — Add comments, highlights, and shapes with customizable styles.
  • Precise measurement tools — Calculate distance, area, and perimeter for technical annotations.
  • Real-time collaboration features — Enable simultaneous document review with version control.
  • Secure document handling — Apply permissions, encryption, and digital signatures to control access.
  • Metadata management — Manage XMP metadata to ensure document categorization and context.
How does Nutrient’s SDK compare to other PDF markup solutions?

Nutrient’s PDF markup SDK stands out by offering more advanced annotation capabilities, real-time collaboration, and enhanced measurement tools, making it a top choice for developers.

  • Greater annotation variety — Supports rich text, ink annotations, and customizable stamp options.
  • Superior measurement precision — Ensures accuracy for technical and engineering use cases.
  • Real-time collaboration efficiency — Enables multiple users to annotate documents simultaneously.
  • Flexible API for customization — Allows seamless integration into web, mobile, and desktop applications.
  • Advanced security and compliance — Provides document security through access control and encryption.