PDF Tool

Protect PDF Online Free

Add a password to any PDF and control what recipients can do — print, copy, or edit. 256-bit AES encryption for maximum security.

No signup required Files deleted in 24h Up to 50 MB free 256-bit AES encryption

Drop your PDF file here

or click to browse — .PDF supported

Choose PDF File

PDF · Max 50 MB free · Up to 200 MB with Pro

Unlock Pro — batch protect, files up to 200 MB, owner password control

Separate open & owner passwords · Digital certificates · Expiry dates

Upgrade — $19/mo

How It Works

Encrypt your PDF with a password in three simple steps

STEP 1

Upload Your PDF

Drag and drop or click to select any PDF up to 50 MB. All types of PDFs are supported — text, scanned, and form-based documents.

STEP 2

Set Password & Permissions

Choose a strong password, set the encryption level, and control what recipients can do — print, copy, or edit.

STEP 3

Download Protected PDF

Click Protect PDF. Your document is encrypted with 256-bit AES and ready to share. Anyone who opens it will need the password.

PDF Security Features

Enterprise-grade encryption in your browser

256-bit AES Encryption

The strongest encryption level supported by the PDF 2.0 standard. The same encryption used by banks and governments worldwide.

Fine-Grained Permissions

Control exactly what recipients can do: allow or block printing, copying text, editing content, adding annotations, filling forms, and page assembly.

Password Strength Meter

Real-time strength indicator helps you create a strong password. Pro users can set separate open and owner passwords for more granular control.

Multiple Encryption Levels

Choose from 256-bit AES (PDF 2.0), 128-bit AES (PDF 1.7), or legacy 40-bit RC4 (PDF 1.4) for compatibility with older PDF readers.

Batch Protection

Pro users can protect multiple PDFs at once with the same or different passwords, ideal for sending personalized protected documents.

100% Private & Secure

Files and passwords are never stored. All processing is done in isolated containers with TLS encryption. Files are deleted within 24 hours.

Protection Features

FeatureFreePro
256-bit AES encryption
Permission controls
File size limit50 MB200 MB
Separate owner password
Batch protection
Digital certificate signing

Frequently Asked Questions

Use 256-bit AES (the default) for the strongest protection with modern PDF viewers. Use 128-bit AES if you need compatibility with older readers. Only use 40-bit RC4 if you're sending to someone using a very old PDF application (PDF 1.4 era).

The open password is required to view the document. The owner password controls what the viewer can do (print, copy, edit) and is typically kept by the document creator. Pro users can set both separately for maximum control.

No. The visual appearance and content of the PDF are completely unchanged. The only difference is that a password dialog appears when someone tries to open it.

Yes. Files and passwords are transmitted via TLS, processed in isolated containers, and permanently deleted within 24 hours. We never log or store your passwords.