Does Dynamsoft Document Viewer require a server-side component?

No. Dynamsoft Document Viewer runs entirely client-side in the browser using JavaScript. There is no backend service to deploy, no server process required, and no document content is transmitted to Dynamsoft servers during rendering. All PDF processing and annotation happens locally in the user's browser. The only network call is for license key validation at initialization.

How does Dynamsoft Document Viewer handle large PDFs?

The SDK uses lazy page rendering — only pages currently visible in the viewport are rendered. Pages outside the visible area are loaded on demand as the user scrolls, keeping memory usage bounded regardless of total page count. Dynamsoft Document Viewer has been tested with documents up to 1,000 pages without performance degradation.

Will Dynamsoft Document Viewer SDK work under a strict Content Security Policy (CSP)?

Yes, with the correct CSP configuration. The SDK uses WebAssembly for PDF rendering, which requires the script-src directive to include 'wasm-unsafe-eval'. This is the recommended approach and is more secure than 'unsafe-eval'. The SDK does not require unsafe-inline for scripts. Full CSP configuration guidance is available in the Dynamsoft Document Viewer security documentation.

Can Dynamsoft Document Viewer display password-protected PDFs?

Yes. The SDK supports password-protected PDF files. The password is passed programmatically via the loadDocument() options object and is used locally for decryption only. The password is never transmitted to any external server.

How are annotations saved in Dynamsoft Document Viewer? Where is annotation data stored?

Annotations are stored in a separate layer and do not modify the original document file. Storage and persistence are controlled entirely by your application — you export annotations as an XFDF file or burn them permanently into the PDF using the SDK's export APIs, then save to your own server or storage system. Dynamsoft Document Viewer does not manage or host annotation data.

DYNAMSOFT DOCUMENT VIEWER

The Document Review and Annotation Layer for you Web Scanning Workflows

View, annotate, search, and edit PDFs and images - client-side, no server required. Integrates with Dynamic Web TWAIN and Mobile Document Scanner.

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Add Review, Annotation & PDF Editing to Your Document Scanning Workflow

Dynamsoft Document Viewer is a JavaScript SDK for embedding document viewing, annotation, and editing capabilities into web applications. It integrates directly with Dynamic Web TWAIN and Mobile Document Scanner, runs entirely on the client side, and requires no server or plugin. The SDK supports PDF, JPEG, PNG, and TIFF files, renders documents of up to 1,000 pages without performance loss, supports Chrome, Firefox, Safari, and Edge, and integrates with React, Angular, Vue, and plain JavaScript. It ships with four viewer types: Edit Viewer for annotation and editing, Capture Viewer for camera workflows, Perspective Viewer for cropping and transformation, and Browse Viewer for multi-page navigation.

Which Product Should I Choose?

	Dynamic Web TWAIN	Mobile Document Scanner	+ Document Viewer
Capture from hardware scanners	✔	—	—
Capture from mobile camera	—	✔	—
Annotation	—	—	✔
Multi-page review UI	Basic	—	Full
Native PDF processing	✔	—	✔

Annotate, Organize and Customize with Ease

Seamless In-Browser Viewing

Load and render large PDFs and image files (TIFF, PNG, JPEG, etc.) with speed and precision.
Swap, share and delete pages within documents.

Rich Annotation Tools

Markup PDFs directly to improve clarity.
Add stamps, freehand shapes or images.
Add, edit and delete annotations in a separate layer.

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Workflow Integration

Customize buttons and tooltips to enhance user experience.
Export markups for downstream processing.
Flexible APIs and full control over UI and behavior.

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Smarter Ways to Work with Text

Boost Accuracy & Clarity with Annotations

Highlight & underline to emphasize, Strikeout to remove.
Add text, stamps, images, shapes or signatures.
Compatible with layered PDFs. Save & share.

Learn more about annotations >

Select & Copy Sections of Text

Find Keywords in Long Documents

Essential Features

Security

All processing done securely within the browser.
No reliance on third-party JavaScript libraries.
No need for a server back-end.

Browsers & File Types

Works with Chrome, Firefox, Safari, Edge browsers.
Supports Windows, macOS, Linux, iOS, Android.
Opens, edits, and saves PDFs and images such as JPEG, PNG and TIFF.

UX Customization

Customizable viewers:

Edit Viewer for editing and annotating documents.
Capture and Perspective Viewers to optimize camera capture experience.
Browse Viewer for navigating multi-page documents.

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