Add powerful electronic and digital signing to your web apps

No server is required to get started. Nutrient Web SDK runs entirely in the browser using WebAssembly technology, enabling you to add electronic signatures and digital signatures with zero infrastructure costs. However, you can optionally pair it with Document Engine when you need remote signing services, HSM integration for secure private keys, or compliance workflows requiring backend processing. The best part? Your frontend code stays identical whether you’re using client-only or adding Document Engine later — only the initialization changes.

Electronic signatures (eSignatures) are simple visual signatures created by drawing, typing, or uploading an image — perfect for everyday paperless workflows like agreements and forms. Digital signatures are cryptographic signatures using X.509 certificates and private keys that provide mathematical proof of authenticity, detect any document modifications, and offer legal validity under regulations like eIDAS and ESIGN. You can use them separately or combine them — for example, using an eSignature for visual appearance with a digital signature for cryptographic security.

The SDK provides built-in validation that automatically verifies certificate chains, checks revocation status via OCSP and CRL, validates timestamps, and detects any document modifications since signing. Validation results show whether signatures are valid, invalid, or have warnings. The UI displays visual indicators (green checkmarks, yellow warnings, red errors) so users immediately see signature status. Programmatically, you can access validation details via API to implement custom workflows, trigger actions based on signature validity, or log validation results for compliance auditing.

Absolutely. A common pattern is using electronic signatures for the visual appearance (hand-drawn signature) combined with digital signatures for cryptographic security. This gives you the user-friendly experience of drawing a signature while adding the legal validity and tamper-detection of certificate-based signing. The SDK makes this seamless — users draw their signature through the UI, and you programmatically apply a digital signature with their certificate in the same operation. This approach satisfies both user experience requirements and compliance mandates.

The SDK supports multiple security models. For testing and development, you can use software-based private keys stored locally. For production, the SDK provides a two-step signing callback that integrates with hardware security modules (HSMs), smart cards via PKCS #11, cloud key management services (AWS KMS, Azure Key Vault), or remote signing services like GlobalSign DSS. The private key never leaves the secure device — only the data to be signed is sent to the signing service, which returns the signature. This ensures maximum security while maintaining the same frontend signing workflow.

Yes. Signature storage is built in. When users create an electronic signature (drawn, typed, or image), you can implement callbacks to store it locally in browser storage or remotely in your database. The SDK provides the signature storage API where you supply save and load functions. Next time the user signs a document, their stored signatures appear for one-click reuse. This dramatically improves user experience for users who sign multiple documents. You control where signatures are stored and can implement compliance requirements like encryption or user-specific storage.

If you already have Nutrient Web Viewer SDK integrated for viewing, adding signing takes minutes. For electronic signatures, add the signature toolbar item and users can immediately draw, type, or upload signatures. For digital signatures, call the `signDocument` method with your certificate and private key. For fill-and-sign forms, signature fields automatically show the signing UI when clicked. The SDK is framework-agnostic and works with React, Angular, Vue, Svelte, vanilla JavaScript, and all other modern frameworks. We provide copy-paste examples for every major framework and signing scenario.

We offer extensive customization for both appearance and behavior. For electronic signatures, users can choose signature colors (black and blue shades), and you can customize available fonts for typed signatures. For digital signatures, configure what information appears in the signature (signer name, date, reason, location), add custom company logos, control field size and position, and create visible or invisible signatures. You can also customize the signing UI itself — hide options, change labels, add custom validation, and match your application’s design system via CSS styling.

Timestamping adds a cryptographic timestamp from a trusted timestamp authority (TSA) to your digital signature, proving when the document was signed. This is critical for long-term validation (LTV); even if the signing certificate expires or is revoked later, the timestamp proves the signature was valid at the time of signing. The SDK integrates with RFC 3161 timestamp authorities. You provide the TSA URL (and optional credentials), and the SDK automatically requests and embeds the timestamp during signing. This ensures signatures remain valid for years or decades, meeting regulatory requirements for archival.

We support all modern frameworks and environments, including: React, Angular, Vue, Svelte, Next.js, Nuxt.js, TypeScript, vanilla JavaScript, jQuery, Blazor, Electron, ASP.NET, PHP, Laravel, and HTML5. The SDK is framework-agnostic — if your framework provides a DOM container and JavaScript, signing will work. All signing operations (electronic signatures, digital signatures, validation) work identically across frameworks. We provide integration guides and runnable examples for every major framework. The SDK also works in progressive web apps (PWAs), WebView components, and kiosk environments.

We provide comprehensive support at every level. Our documentation includes step-by-step guides for electronic signatures, digital signatures, certificate generation, validation workflows, and compliance requirements. You get complete API reference documentation, live code examples you can run, and best practices for each signing scenario. Interactive demos let you test signing features before integrating. Standard support includes email support, community forums, and our extensive knowledge base. Premium support adds dedicated support engineers, SLA guarantees, and compliance consultation. During your free trial, you have full access to documentation and support to properly evaluate signing capabilities for your needs.