Power High-Stakes Document Interactions in Your Product
WebViewer runs the document layer of applications, where the document is the work: contracts that get signed, claims that get approved, and filings that have to be exact. More of that content now comes from an LLM or an extraction pipeline, but review can’t be automated. Someone still has to verify what the model produced.
WebViewer is where that verification happens. High-fidelity rendering, search, redaction, annotation, comparison, and editing sit beside the source document in your own UI, so a reviewer can confirm or correct model output and act on it without switching tools.
Add the Viewer to Your App
Install the package, point it at a document, and mount it to an element on the page. Wrappers for React, Angular, and Vue are available.
import WebViewer from '@pdftron/webviewer'
const viewerElement = document.getElementById('viewer');
WebViewer({
path: '/webviewer/lib',
initialDoc: '/path/to/doc.pdf',
}, viewerElement).then(instance => {
// call apis here
});In-Browser PDF and Office Editing
WebViewer’s editing add-ons extend the core viewer with PDF, DOCX, and spreadsheet editing. Enable each capability as needed using the same API and UI framework, so the integration and interface stay consistent across all three.
Document Interaction & Processing Capabilities
REVIEW AND COLLABORATION
Review and Collaboration
Add 35+ annotation types or build custom markup tools, with support for collaborative review.
VIEW CAPABILITIES
TEXT EDITING
COMPARISON
REDACTION
FORM CREATION
DIGITAL SIGNATURES
MEASUREMENT
PAGE MANIPULATION
DOCUMENT GENERATION
One SDK for PDF, Office, CAD, and Images
One SDK and one JavaScript API cover every file type your app handles: viewing and annotation for PDF and 30+ formats, including Office (DOCX, XLSX, PPTX) and common image formats, as well as editing for PDF, DOCX, and Excel files in the browser. Learn it once and reuse it everywhere, instead of stitching together a separate library per format.
Build Workflows That Fit Your Application
Configure toolbars, panels, theming, and navigation to match how your users work, then ship it inside your existing application. WebViewer's modular UI is WCAG 2.2 Level AA-compliant by default, so accessibility is one less thing to retrofit.
Control Document Behavior with APIs
Everything in the viewer is scriptable through the JavaScript API: drive the viewer programmatically, respond to document events, and wire interactions into your app. Processing runs in the browser via WebAssembly, so document content is never transmitted to Apryse’s infrastructure, which keeps on-premise and air-gapped deployments straightforward.
What Developers Build with WebViewer
AI Document Review
A human review step for model-generated or extracted content, before it enters your system.
Contract Lifecycle Management
A browser-based contract review and approval flow with redlining and digital signatures.
Document Management Systems
A unified document viewer for PDF, Office, and image files, with annotation and search.
Claims Processing
In-workflow document verification with redaction and form-based data capture.
Compliance & Audit
A version comparison and approval audit trail for compliance workflows.
Customer Onboarding
An embedded document experience for onboarding: form filling, e-signature collection, and document review in one step.
Supported Integrations
Why Teams Choose WebViewer
WebViewer is the only JavaScript SDK that views and edits PDF, DOCX, and spreadsheets natively in the browser, through one consistent, WCAG 2.2 Level AA interface, from a single vendor, with no server dependency for processing.
Client-Side
Client-side WebAssembly processing. Document content never leaves the browser.
WebViewer FAQs
Add the WebViewer library to your project and initialize it with a few lines of JavaScript. WebViewer provides ready-to-use examples for React, Angular, and more. See the Getting Started Guide or the interactive demo to learn more.
WebViewer runs client-side. Document processing happens in the browser through a WebAssembly module built from Apryse's C++ core, and no document content is transmitted to Apryse infrastructure. The default client-only deployment needs no server. An optional Docker backend is available when you need broader format support, such as CAD, or need to support older browsers.
The base Web SDK covers viewing and annotation for PDF and 30+ file formats, including Office (DOCX, XLSX, PPTX) and common image formats like JPG, PNG, and TIFF. Some formats, including CAD, render through the optional Docker backend or a custom server.
Yes. WebViewer edits Word (DOCX) and Excel (XLSX and XLS) natively in the browser through the DOCX Editor and Spreadsheet Editor add-ons, alongside in-line PDF editing. Viewing DOCX and Excel files needs no add-on; editing them does.
The WebViewer UI is WCAG 2.2 Level AA compliant across the viewer, DOCX Editor, and Spreadsheet Editor, with full keyboard navigation, ARIA support, screen reader compatibility, and customizable focus indicators. That supports Section 508 and the European Accessibility Act requirements.
Yes. WebViewer is where a reviewer checks model-generated or extracted content before it is accepted, with the source document and the review tools in one place. See our take on the last mile of AI document review.
WebViewer natively supports right-to-left language (RTL) content, so you can build applications for global regions without bolting on separate handling. In addition to RTL content rendering, the WebViewer UI is now localized into Arabic, Hebrew, Persian, and Urdu.
Yes. The Web SDK ships with TypeScript type definitions, so you get autocomplete and type checking across the API in TypeScript projects, alongside support for JavaScript and frameworks like React, Angular, Vue, and Next.js.
WebViewer loads its WebAssembly and viewer assets on demand rather than all at once, and PDF linearization renders the first page immediately while the remaining pages stream in. You self-host the static assets, so you control caching and delivery. For exact asset sizes, lazy-loading options, and performance tuning, see the getting started documentation.
Open-source libraries like PDF.js render PDFs in the browser, and for read-only display of simple PDFs they can be enough. The gap opens once the work goes past viewing. PDF.js is a rendering engine: it does not edit PDFs, does not view or edit Office files like DOCX and XLSX, offers only basic annotation, and leaves accessibility, security patching, and ongoing maintenance to your team. WebViewer is the only JavaScript SDK that views and edits PDF, DOCX, and spreadsheets natively in the browser, through one consistent WCAG 2.2 Level AA interface, from a single vendor, with no server dependency for processing. The decision is less about license cost than about total cost: the engineering time to build and maintain viewing, Office support, editing, annotation, and accessibility yourself, versus integrating them already solved and supported. For a side-by-side walkthrough, see the Apryse blog Commercial PDF Viewer or Open-Source PDF Viewer.
WebViewer is a commercial SDK. A free trial key includes access to every add-on, so you can evaluate the whole thing before buying. For production, the editor and other add-ons are licensed separately from the base SDK. Get a trial key at dev.apryse.com.
