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Protect PDF – Add Password to PDF Free Online
🔒 Free  ·  No Signup  ·  No Watermark  ·  100% Private

Protect PDF File
Add Password to PDF Free

Lock your PDF with a strong password and AES-128 encryption instantly. Control printing, copying, and editing permissions. Works entirely in your browser — your files never leave your device.

PDF
Original PDF
🔒
PDF
Password Protected
100%
Free Forever
0s
Server Upload Time
AES
128-bit Encryption
✓
Permission Control

🔒 PDF Password Protector

Upload your PDF, set a strong password, configure permissions, and download your encrypted PDF instantly.

📂 Step 1 — Upload PDF File
🔒
100% Private: Your PDF is never uploaded to any server. All encryption is performed locally in your browser using the PDF-lib library. Your file stays on your device at all times.
📄

Drag & Drop your PDF here

or click to browse files from your device

✅ PDF
🔑 Step 2 — Set Password
💡 Strong Password Tips
Aa Uppercase + Lowercase 123 Numbers !@# Special Characters 8+ Characters
🛡️ Step 3 — Set Permissions

Control what users can do with the PDF after opening it. Checked = allowed.

⬇️ Step 4 — Download Protected PDF
✅
PDF Protected Successfully!
Your PDF has been encrypted and locked with the password below.
🔑  —

Why Use This Tool

The Best Free PDF Password Protector

Secure, private, and fully browser-based — everything you need to lock your PDF files with strong encryption and permission controls.

🔒
100% Private & Secure
Your PDF file is processed entirely in your browser using PDF-lib. It is never sent to any server. Your sensitive documents stay on your device at all times.
🛡️
AES 128 / 256-bit Encryption
Choose between AES-128 (standard), AES-256 (maximum security), or RC4-128 (compatibility mode for older PDF readers). Industry-standard encryption algorithms.
🔑
Open + Owner Passwords
Set an open password so only authorised users can view the document. Optionally set a separate owner password to control who can change permissions or remove protection.
🛠️
Full Permission Control
Restrict printing, copying text, editing content, adding annotations, filling forms, and assembling pages. Choose exactly what recipients are allowed to do.
💪
Real-time Password Strength
Live password strength meter evaluates your password as you type — Weak, Fair, Good, or Strong. Visual tips highlight missing complexity requirements.
⚡
Instant Encryption
PDF encryption happens in your browser in seconds using PDF-lib. No server processing or upload wait times. Your protected PDF downloads immediately.
📋
Password Confirmation
Enter your password twice to prevent typos. Live match indicator confirms both entries match before you can protect the file — no accidental lockouts.
👁️
Show / Hide Password
Toggle password visibility on all password fields. Easily verify what you've typed before locking your document — especially useful for complex passwords.
📱
Works on Any Device
Fully responsive design works perfectly on desktop, tablet, and mobile. Protect your PDF files from anywhere, any time, for free — no app to install.
Simple Process

Password Protect PDF in 4 Steps

From upload to encrypted download in under a minute. No sign-up, no software installation required.

1
Upload Your PDF
Drag and drop your PDF file, or click to browse. Your file is never sent to any server — it stays 100% on your device.
2
Set Your Password
Enter a strong password and confirm it. Use the real-time strength meter to ensure your password is secure enough.
3
Configure Permissions
Choose whether recipients can print, copy, edit, annotate, or fill forms. Full control over what users can do with your PDF.
4
Download Protected PDF
Click "Protect PDF". Your encrypted file downloads instantly — ready to share, email, or store with confidence.
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FAQ

PDF Password Protection — FAQs

Everything you need to know about adding password protection to PDF files.

Is this PDF password protector really free?
Yes, 100% free with no hidden fees, no subscription, and no signup required. Use it as many times as you need, with any PDF file, completely free forever.
Is my PDF uploaded to a server?
No. This tool runs entirely in your browser using PDF-lib. Your PDF file is never sent to any server — all encryption happens locally on your own device. Total privacy.
What is the difference between Open and Owner passwords?
The Open password (also called User password) is required to view the PDF. The Owner password (also called Permissions password) controls who can change security settings or override restrictions — useful when you want to share a restricted PDF but retain master control.
Which encryption level should I use?
AES-128 is the best balance of security and compatibility. AES-256 provides maximum security and is recommended for highly sensitive documents. RC4-128 is for compatibility with very old PDF readers (pre-2004).
Will the protected PDF work in all PDF readers?
Yes. The AES-128 encrypted output is compatible with Adobe Acrobat, Adobe Reader, Foxit, Chrome's built-in PDF viewer, macOS Preview, and virtually all modern PDF reading software.
What if I forget the password I set?
There is no way to recover a forgotten PDF password — this is by design as it ensures your security. Always save your password in a secure password manager before locking your PDF.