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Encrypt PDF Online – Free PDF Encryption Tool

Password-protect your PDF files with strong encryption. Set a user password to restrict viewing and an optional owner password to restrict editing. All processing stays in your browser – nothing is uploaded to any server.

1
Upload
2
Protect
3
Download
📄

Upload your PDF

Click or drag & drop — max 50 MB

Weak
Minimum 6 characters. Strong passwords use a mix of letters, numbers, and symbols.
If set, this password is required to change permissions. Leave blank to use the user password.
💡 How encryption works:
Your PDF is encrypted entirely inside your browser. The user password is required to open the document. The owner password (if set) restricts editing, printing, and copying. Your passwords are never transmitted anywhere. Keep them safe – without the password, your PDF cannot be opened.

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📄 Original (Page 1)

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🔒 Protected File

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Not encrypted yet
Click "Encrypt PDF" to protect this file

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Why encrypt your PDF?

Encrypting your PDF with a password adds a critical layer of security. It ensures that only authorized individuals can view or modify the document. This is essential for sensitive documents like contracts, financial statements, medical records, or personal information. With our tool, you control who can open, print, copy, or edit your PDF – all without uploading to any server.

📤
UPLOAD

Choose your PDF file

🔑
SET PASSWORD

Create a strong password

🔒
ENCRYPT

Protect your document

⬇️
DOWNLOAD

Save the encrypted PDF

How to use this tool

  1. Upload your PDF. Click or drag & drop your file into the upload zone.
  2. Set a user password. This password will be required to open the PDF. The strength meter helps you create a secure password.
  3. Set an owner password (optional). This password restricts editing, printing, and copying. Leave blank to use the user password for permissions.
  4. Configure permissions. Choose what users can do with the document – printing, copying, and editing.
  5. Click "Encrypt PDF". The tool encrypts your document locally in your browser.
  6. Download. Save the encrypted PDF to your device. Remember your passwords!

Frequently Asked Questions

You can choose between AES-256 (the modern PDF 2.0 standard, recommended for maximum security) and RC4-128 (a legacy mode kept for compatibility with very old PDF readers). AES-256 is selected by default.
No. All processing is done locally in your browser. Your files and passwords never leave your device.
The user password is required to open and view the PDF. The owner password controls permissions – printing, copying, and editing. If only a user password is set, anyone with the password can do everything. If both are set, the owner password grants full control.
If you forget the user password, the PDF cannot be opened. There is no backdoor or recovery method. We strongly recommend using a password manager and keeping a backup of your passwords.
Not directly. If a PDF already has a password, please remove it first (with an unlock/decrypt tool), then upload the unlocked file here to add your new password. This tool will let you know if it detects an existing password.

🔒 The safest way to encrypt PDFs

Whether you're protecting sensitive business documents, personal information, or academic work, our PDF encryption tool gives you complete control. No sign‑up, no watermarks, and total privacy – your files and passwords stay on your machine. Start encrypting now.