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Lock PDF

Protect your PDF with strong password encryption and control who can open or edit it.

How to Password Protect a PDF

Step 1

Upload your PDF

Select or drag and drop the PDF you want to secure.

Step 2

Set a Password

Type a strong password to encrypt your document.

Step 3

Download PDF

Click lock and instantly download your protected file.

Why Secure PDFs with ModifyPDF?

The safest way to protect sensitive information from unauthorized access.

Strong Encryption

We use advanced encryption standards to lock your files.

Restrict Permissions

Prevent copying, editing, and printing of your document.

Instant Processing

Files are locked immediately without long waiting times.

Mobile Ready

Protect files on-the-go directly from your smartphone.

100% Free

No hidden fees, no subscriptions. Use it for free.

Total Privacy

Your files never leave your device, ensuring maximum confidentiality.

Frequently Asked Questions