Drag & Drop PDF Files Here

or click to select files

What is ZyncPDF?

ZyncPDF is an open-source, privacy-first suite of powerful PDF tools built for speed, simplicity, and total user control. We believe your documents should stay yours — always. Every operation in ZyncPDF happens directly inside your browser, meaning your files never leave your device. With no uploads, no tracking, no ads, and no registration, ZyncPDF provides a smooth, secure, and 100% private experience for all your PDF tasks — from converting and merging to compressing and editing.

Why use our PDF Encryption tool?

  • Completely Free & Unlimited: Protect as many PDFs as you want.
  • Privacy First: Encryption happens locally in your browser. Your files never leave your device.
  • Open Source: Verify our privacy claims and contribute.
  • Strong Encryption: AES-256 available for maximum security.
  • No Registration Required: Use instantly.

How to add a password to your PDF:

  1. Step 1: Drag and drop your PDF into the upload area, or click to select it.
  2. Step 2: Enter and confirm the new password in the options box.
  3. Step 3: Click "Process Files" to encrypt your PDF.
  4. Step 4: Download your new, password-protected PDF.

Frequently Asked Questions (FAQ)

Is encryption done on your servers?

No. Everything happens in your browser. Your files are never uploaded, ensuring complete privacy.

What encryption strength is used?

We support strong AES-256 encryption, offering robust protection for your PDFs.

Can I remove a password later?

Yes—use our Remove PDF Password tool to decrypt PDFs you have access to.