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100% Private In-Browser Tool • Zero Uploads

Protect PDF (PDF Locker)

Password-protect your PDF files directly on your device with local client-side encryption.

Protect PDF (PDF Locker)

Password-protect and encrypt PDF documents locally in your browser with AES-256. 100% private.

Drag & drop image files here, or browse

Select or drop a PDF document to password-protect.

Zero-knowledge local security: Your documents and passwords stay strictly on your device. We use standard client-side AES-256 Web Crypto encryption; zero bytes leave your device.

Step-by-Step Guide

How to use Protect PDF (PDF Locker)

1

Select PDF Document

Choose or drag any unencrypted PDF file into the local dropzone.

2

Set Document Password

Choose a strong password to restrict viewing or unauthorized access.

3

Download Encrypted PDF

Save the protected PDF file directly to your device.

Features & Benefits

Why use ImgZero for Protect PDF (PDF Locker)?

Zero-upload client-side security architecture
Standard PDF Security Handler compatibility
No passwords or encryption keys ever leave your device

Frequently Asked Questions

Is my password sent to ImgZero servers?

Never. All document processing and encryption occurs purely in your browser's local sandbox.

What PDF viewers can open protected files?

Protected files adhere to standard PDF encryption specifications, compatible with Adobe Acrobat, Apple Preview, and modern browsers.

100% Client-Side Privacy Guarantee

Your files stay on your machine. No server uploads and no file-content tracking.

Zero Server Bandwidth Delay
Instant Web Worker Speed
Works Fully Offline