ThinPDF

Add Password to PDF Free Online

Secure your PDF documents with password protection using AES-256 encryption. Fast, secure, and completely free.

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Drag and drop your PDF here

Maximum file size: 100MB

encrypted AES-256 Encryption
privacy_tip 100% Private
speed Instant Protection
money_off Completely Free

How to Password Protect PDF Files Online

  1. Upload your PDF: Click "Choose File" or drag and drop your PDF file into the upload area.
  2. Set password: Enter a secure password that will be required to open the PDF.
  3. Protect your PDF: Click the "Protect PDF" button to encrypt your document.
  4. Download result: Once complete, download your password-protected PDF file.

About PDF Password Protection

PDF password protection uses AES-256 encryption, the same military-grade security standard used by governments and financial institutions worldwide. Once protected, your PDF will require the correct password to be opened, ensuring your sensitive documents remain confidential. This is essential for protecting financial records, legal documents, contracts, and any other sensitive information.

Security & Privacy

Your security and privacy are our top priorities. We never store your password - it's used only for encryption and then immediately discarded. All uploaded files are automatically deleted from our servers after 10 minutes. Your documents are processed securely and never shared with third parties.