lockPDF Security Tool
Protect PDF Files Online
Add password protection and AES encryption to confidential PDF documents — 100% free & secure.
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Drop your PDF file here to protect
or click to browse from your computer
Complete Guide & Overview
Protect PDF Online for Free — Password Encryption & Security
Add AES password protection and encryption to confidential PDF files. Prevent unauthorized opening, printing, and copying. 100% free and private.
Sending confidential tax forms, medical records, or sensitive business proposals via email? PDFPookie’s Protect PDF tool allows you to encrypt PDF documents with custom passwords in seconds.
Our tool applies strong AES encryption algorithms to lock your document. Without the correct password, unauthorized viewers cannot open, view, or extract data from the file.
100% free with transport security. Files are automatically purged from temporary server storage immediately after encryption.
How to use Protect PDF online for free
1
Upload PDF Document
Drag and drop your PDF or select a document from your device.
2
Set Strong Password
Type a secure password to encrypt your document.
3
Protect & Download PDF
Click "Encrypt & Save PDF" to download your password-protected file instantly.
Why use PDFPookie for Protect PDF?
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AES Encryption Security
Protect your PDF with strong password encryption standard across all modern PDF readers.
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Prevent Unauthorized Access
Block unauthorized viewing, copying, and printing of sensitive document contents.
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Instant Encryption
Encrypt documents in seconds with zero file size limits.
Common Use Cases & Examples
📌 Financial & Payroll Documents
Encrypt monthly employee paystubs or corporate financial statements before emailing.
📌 Legal Contracts & Agreements
Add password security to client contracts and non-disclosure agreements.
📌 Medical & Personal Records
Protect medical diagnosis forms, insurance claims, and personal identity documents.
📌 Academic Test Papers
Password protect exam papers before distributing them to remote test proctors.
Frequently Asked Questions (FAQs)
Any standard PDF reader (Adobe Acrobat, Chrome, Apple Preview) will prompt the user to enter the password before revealing any text or images.