How to Embed Secure Document Viewing in Your Application

Compliance regulations in financial services, healthcare, and other regulated industries control where document data is stored and processed. If your application sends sensitive files to a third-party API for rendering or OCR, that network hop introduces risk. Some open-source libraries relay document content to cloud services for certain operations, creating a compliance gap your security team will flag during review.

With Apryse WebViewer, you can embed secure, browser-based document viewing in your application without sending sensitive document data to a third-party server. WebViewer renders PDFs and other file formats directly in the browser using WebAssembly, which allows sensitive banking documents to stay on the user's machine.

For a financial services platform, this architecture answers the question compliance teams ask first: where does the data go? In this article, we cover what embedded viewing means, how rendering works in WebViewer, and important security and deployment considerations.

While you can use an API to connect third-party capabilities to your application, embedded viewing capability performs all the rendering within your application, with no external dependencies. You can easily install WebViewer via npm and initialize using your trial license key, exposing a Core namespace for document logic and a UI namespace for the interface. This means that WebViewer performs all the document capabilities included in the SDK fully on the client-side.

The WebViewer core SDK package covers viewing and annotation across PDF and more than 30 formats, including DOCX, XLSX, and common image types. This puts secure document viewing all with one component under one license, supporting financial document workflows such as statements, agreements and forms. While WebViewer does support much more advanced functionality than simple viewing, including PDF, DOCX and Spreadsheet editing, these features are broken out into paid add-ons, so you don’t pay for advanced features you don’t use.

WebViewer compiles Apryse's C++ rendering core to WebAssembly, so processing runs at near-native speed inside the browser instead of on a remote server. In regulated environments, where a signed loan disclosure or a trading confirmation never transmits to third-party infrastructure for rendering, this provides better security by eliminating a network hop.

WebViewer also runs under a Content Security Policy and does not require unsafe-inline or unsafe-eval. This helps banks and fintech platforms that frequently operate under hardened CSP requirements set by internal security review.

Embedded viewing options in this category share a common shape but differ in where documents are processed and how editing works underneath the viewer.

For a financial services platform, the deployment and editing rows matter most. Foxit, Nutrient, and Syncfusion each offer capable viewing experiences, and Syncfusion benefits from bundle economics as one product inside a much larger component suite.

Data residency and document editing are key areas of the comparison. For example, a firm that needs a signed disclosure edited in place, in the browser, without a document server, and without the file ever leaving its environment, is evaluating a narrower architectural requirement than viewing alone.

Browser-based rendering gives you secure architecture, limiting potential vulnerabilities. A loan file or account statement that never leaves the browser cannot be intercepted in transit to a rendering server, because there isn't one. This applies to every document the base SDK renders, with no add-on required.

The Security add-on for WebViewer layers on PDF encryption (128-bit or 256-bit AES), permission controls that restrict copying or printing, and watermarking with timestamp support, all applied in the browser. A firm distributing a signed disclosure to a borrower can watermark it with the recipient's name and access time, and restrict printing, without a server round trip. For KYC and AML workflows that need to permanently remove sensitive identifiers rather than just restrict access to them, the Redaction add-on finds and removes text or image content matching patterns like account or Social Security numbers, permanently removing them.

To further support your platform’s security requirements, Apryse has obtained independent compliance verification including ISO 27001 and SOC 2, which financial services procurement and infosec teams typically require during vendor review.

The client-side architecture supports compliance across multiple regulatory frameworks:

Financial services: Self-hosted deployment keeps customer financial records, loan documents, and account statements within the institution's perimeter. AES-256 encryption and permission controls support data protection requirements under regulations like GLBA and PCI DSS.

Healthcare: Local processing means PHI never leaves the customer's environment. Redaction, sanitization, and encryption provide the building blocks for HIPAA-compliant document workflows.

Government and defense: Air-gapped deployment and the absence of external data transmission support environments operating under FedRAMP-authorized infrastructure or ITAR restrictions.

Legal: Attorney-client privileged documents remain within the firm's infrastructure. Annotation layers preserve review trails without altering original documents.

When you use a frustrating user interface, it’s all you notice about the application. On the other hand, a good, intuitive UX is invisible. If a user sees a separate viewer application or a jarring transition from the surrounding platform, it can be confusing. WebViewer's modular UI mounts inline and can be customized to match your product's design system.

Accessibility is built into the WebViewer UI. WebViewer's core interface meets WCAG 2.2 Level AA, with keyboard navigation, ARIA support, and screen reader compatibility, which matters for retail banking platforms serving customers under accessibility regulation. Embedded viewing also supports in-place review: a loan officer or compliance analyst can annotate a document and hand it to a second reviewer without downloading, editing, and re-uploading the file. Annotations live in a separate data layer, so the underwriting or KYC review trail is built without altering the original document.

WebViewer supports three deployment models. The right one depends on your browser support requirements and existing infrastructure.

Flexible deployment options can run client-only and avoid a server dependency entirely. A bank supporting a legacy internal underwriting tool on older browsers may need the Docker backend to reach that audience without dropping support.

Whether your application is handling a 200-page loan package or a multi-year brokerage statement, your document processing solution needs to display it smoothly. Users can’t wait for the whole file to load before seeing anything, or they will turn to ad-hoc workflows.

WebViewer uses linearization and byte range requests to display the first page immediately, downloading the rest of the file incrementally. Viewer Optimized PDF extends this further by embedding page thumbnails, so a relationship manager sees a preview before the WASM module finishes initializing.

The same architecture applies wherever an application shows sensitive documents without routing them through a third party. In any regulated industry with sensitive document requirements, browser-based rendering keeps sensitive document content off third-party infrastructure.

Healthcare: Platforms displaying clinical records under HIPAA keep patient data within the provider's infrastructure. Redaction removes PII from documents shared across care teams.

Legal: Case management systems assemble filings that must stay auditable. Annotation layers support multi-party review without altering original documents.

Government: Agencies processing classified or controlled unclassified information (CUI) require air-gapped deployments. Client-side rendering eliminates external data transmission.

Insurance: Claims processing platforms handle policyholder documents, medical records, and adjuster reports that require strict access controls and audit trails.

To use WebViewer in your project, start by getting your trial key to access all SDK features for free. Next, you’ll use the Quick Start guide in our documentation to select your library or framework. Finally, follow the steps in the framework-specific guide to download and initialize WebViewer.

The process looks like this:

For most frameworks, the entire process takes 5-10 minutes and can be started instantly.

To learn more about WebViewer features and licensing, contact sales.

Q:Can PDF viewing happen entirely in the browser? 

A: Yes. A WebAssembly-based viewer like WebViewer renders PDF content using the browser's own processing power, with no server involved. This differs from cloud-based viewers, which process the document on a remote server first.

Q:Do PDF viewers send data externally? 

A: It depends on the architecture. A client-side viewer transmits nothing, because there is no server in the rendering path. A cloud API-based viewer processes the document on the vendor's infrastructure, which means the file content leaves the user's device.

Q:What should you look for in a secure PDF viewer? 

A: Start with where rendering happens: client-side architectures keep document content off third-party servers by design, not by configuration. From there, check for independent compliance certifications like ISO 27001 or SOC 2, encryption and permission controls, and accessibility support if the audience includes users under WCAG or Section 508 requirements.

Q:How does embedded PDF viewing improve user experience? 

A: Embedded PDF viewing keeps the user inside your application instead of redirecting them to a separate viewer or plugin. A well-integrated viewer matches your product's interface, loads large documents progressively, and supports in-place review actions so the user never leaves your product to work with the document.

Q: What is the difference between client-side and server-side PDF rendering?

A: Client-side rendering processes the document in the user's browser using technologies like WebAssembly. No document data leaves the device. Server-side rendering sends the document to a backend service, which processes it and returns rendered output. Client-side rendering eliminates the network hop and the compliance risk of transmitting document content to external infrastructure.

Q: What file formats can an embedded document viewer support?

A: It depends on the SDK. Some viewers handle PDF only. More comprehensive SDKs support PDF and 30 or more additional formats, including DOCX, XLSX, PPTX, and common image types like JPG, PNG, and TIFF. Broader format support reduces the number of tools your application needs to handle different document types.

Q: How do embedded document viewers handle large files?

A: High-performance viewers use linearization and byte range requests to display the first page immediately while downloading the remaining pages incrementally. This means a user opening a 500-page document sees the first page in seconds rather than waiting for the full file to download. Some viewers also support pre-rendered thumbnails for faster navigation.

Q: What compliance certifications should a document viewer vendor have?

A: Look for ISO 27001 (information security management) and SOC 2 Type II (security, availability, and confidentiality). These certifications demonstrate that the vendor follows audited security practices. For specific industries, verify that the viewer's architecture supports your regulatory requirements: HIPAA for healthcare, GLBA for financial services, and GDPR for organizations handling EU personal data.