Protect PDF - Encrypt & Password Protect Your PDFs
Add password protection to your PDF files instantly. Free, secure, and works in your browser. Encrypt sensitive documents with strong passwords.
Protect your sensitive PDF documents with military-grade AES-256 encryption. Our free online tool adds password protection to your PDFs instantly, ensuring only authorized users can access your confidential information.
Set user passwords to prevent unauthorized opening, or owner passwords to restrict editing, printing, and copying. All encryption happens locally in your browser - your files never leave your device, guaranteeing complete privacy and security.
Perfect for protecting business contracts, financial statements, legal documents, and any sensitive PDF files you need to share securely.
Why use this tool
- Military-grade AES-256 encryption for maximum security
- Add user passwords to prevent unauthorized access
- Set owner passwords to restrict editing, printing, and copying
- Works entirely in your browser - no file uploads
- No file size limits - protect PDFs of any size
- Instant encryption in seconds
- No registration or account creation required
- Completely free with no watermarks or restrictions
How it works
- Click "Select PDF" or drag and drop your PDF file
- Enter a strong password to protect your document
- Click "Protect PDF" and download your encrypted file
Frequently asked questions
How secure is PDF password protection?
Our tool uses AES-256 encryption, the same military-grade standard used by governments and enterprises worldwide. This provides extremely strong protection against unauthorized access.
What's the difference between user password and owner password?
A user password prevents anyone from opening the PDF without the password. An owner password allows opening the PDF but restricts actions like editing, printing, or copying content.
Are my files uploaded to a server?
No. All PDF encryption happens entirely in your browser using client-side JavaScript. Your files never leave your device and are not uploaded to any server.
Can password-protected PDFs be unlocked?
Only with the correct password. Strong passwords with AES-256 encryption are virtually impossible to crack without knowing the password.
Will password protection reduce PDF quality?
No. Password protection only adds encryption metadata to your PDF. All content, images, formatting, fonts, and quality remain exactly as they were.
Is there a file size limit?
No, there are no file size limits. You can protect PDFs of any size completely free.
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