How to Password Protect a PDF Online

Need to send a sensitive tax document, legal contract, report, or other PDF? Password protection can be useful when you want the recipient to have the file but still require a password before the protected copy can be opened.

Fortunately, you don't need expensive software to secure your PDF files. FileLocker uses AES-GCM encryption to protect any PDF directly in your web browser, completely for free.

Privacy First

Because FileLocker processes your PDF using JavaScript directly on your device, your sensitive document is never uploaded to our servers. Your document is processed entirely on your device.

How to Password Protect a PDF Step by Step

  1. 1Open the FileLocker ToolGo to our free File Protection tool.
  2. 2Select your PDFClick "Upload from PC or Mobile" and select the PDF document you want to protect.
  3. 3Create a Strong PasswordEnter a password that only you and the intended recipient will know. Do not forget this password, as it cannot be recovered!
  4. 4Save the .vault FileClick "Lock & Save File". FileLocker will encrypt the PDF and save it as a .vault file to your device.

How to Open a Password-Protected PDF Later

When your recipient receives the .vault file (via email, WhatsApp, or cloud storage), they simply go to the Unlock Tool, select the file, enter the password you gave them, and it restores the original PDF document after the password is verified.

Other Ways to Password Protect a PDF

FileLocker is not the only way to password protect a PDF. Here are common alternatives:

  • Adobe Acrobat: Adobe provides built-in PDF protection features in Acrobat. Availability of specific features can depend on the Acrobat edition or plan.
  • Microsoft Word / LibreOffice: If you are starting from a Word document, both Microsoft Word and LibreOffice can export password-protected PDFs.
  • macOS Preview: On a Mac, you can add a password to a PDF directly from the Preview app when exporting.

FileLocker is useful when you want a browser-based workflow that processes the PDF on your device and produces a protected .vault file. The recipient can then use FileLocker's unlock tool with the correct password.

Frequently Asked Questions

Can I password protect a PDF for free?

Yes. FileLocker provides free, browser-based PDF protection using AES-GCM encryption. No subscription or account is required.

Do I need Adobe Acrobat to password protect a PDF?

No. Adobe Acrobat is one option. FileLocker provides another browser-based way to protect a PDF without installing desktop software.

Is my PDF uploaded to a server?

No. FileLocker processes your PDF entirely on your device. Your file is never uploaded to a server.

Can the recipient open my protected PDF without FileLocker?

No. A FileLocker-protected PDF is saved as a .vault file, which requires the FileLocker unlock tool and the correct password to open.

Ready to secure your PDF?

Protect a PDF Now