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The Leading Document & PDF Annotation Library

Let your users annotate and collaborate around PDF, Word, Excel, PowerPoint, and 30+ formats in your web, mobile, server, and desktop applications.

Standard & Custom Annotation Types

Built-in support for 26 standard PDF annotation types. For example, users can take notes, make comments, highlight, add shapes, apply freehand ink drawings. Or create your own custom annotations.

ISO Compliant Annotation Interchange

Preserve the original document by keeping dynamic annotations & discussions in an external XFDF file — a standards-compliant format for annotation interchange.

Real-time Collaboration Support

Let users annotate & exchange messages in real-time across devices and platforms. Create security rules to limit who can view, edit, or comment on annotations.

Annotation Workflows

Support countless use cases by dynamically generating the XFDF file from a database. Track changes in an audit trail. Merge or separate annotations. Add approval logic. Support offline annotation. And more.

Accurate Annotation Rendering

Ensure a trustworthy representation of annotations across all devices and browsers with built-in support for 'Appearance Streams'.

Drop-In UIs with Source Code Control

Embed slick & ready-to-use annotation tools & widgets. Or, create unique annotation experiences with the power & flexibility of complete source code customization. No limits!

Try our SDK for free today


Free Trial

Get unlimited trial usage of PDFTron SDK to bring accurate, reliable, and fast document processing capabilities to any application or workflow.

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