PHP PDF Digital Signature Library

Nutrient Web SDK is a JavaScript library for signing PDF documents with an electronic signature or with encrypted certificate-based digital signatures. It is fully compatible with PHP and offers developers an API to create, validate, and display digitally signed documents, as well as a beautiful UI for hand-drawn electronic signatures in any PHP-based web app.

Try for free Launch demo

Nutrient SDKs are deployed in some of the world’s most popular applications, such as those made by Autodesk, Disney, UBS, Dropbox, IBM, and Lufthansa.

Key capabilities

• Create digital signatures — Digitally sign by using a private key

• Validate digital signatures — Verify the certificate and signature

• eSignatures — Add drawn, scanned, or typed electronic signatures

• Signature storage — Store locally or remotely for future reuse

• Events — Trigger workflows or automations

• Customizable UI — Hide buttons, match your look & feel, and more

• Client-side — Sign PDFs directly in the browser (no server needed)

• Extendable — Add forms, annotation, editing, and more

Guides for signatures

Introduction to signatures
Learn about the basics of PDF signatures

Add an ink electronic signature
How to add an electronic signature (eSignature) to a PDF document

Electronic signature storage
How to implement a mechanism for storing signatures

Digital signatures lifecycle
How to add digital signatures to a PDF document and timestamp or validate them

Supported digital signature methods
Learn about the supported digital signing methods and algorithms

Electronically sign with a certificate
How to use electronic signatures and digital signatures together

Fill and sign forms
How to programmatically or manually fill and sign forms in a PDF

FAQ

Here are a few frequently asked questions about signatures in Nutrient Web SDK.

What types of signatures can I add to a PDF with this library?

You can add both electronic signatures and encrypted certificate-based digital signatures.

Can I validate signatures within my app?

Yes, the library allows you to validate certificates and signatures directly within your app.

Is server-side processing required for signing PDFs?

No, all signing processes can be done entirely on the client side without a server.

Can I store electronic signatures for reuse?

Yes, the library provides options to store signatures locally or remotely for future use.

Is the signature UI customizable?

Yes, you can fully customize the signature UI to match your app’s design and workflow requirements.