PDFBook Protect PDF lets you password-protect and encrypt a PDF file to restrict unauthorized access. The encryption runs entirely in your browser with AES-256, so your password and document are never sent to any server. You get a protected copy that asks for the password whenever it is opened.

Encryption happens locally in your browser. PDFBook never sees your password or your document, so your files stay private while you protect them.

Key Facts

  • Encrypts with AES-256, the same strength trusted by banks
  • Password and document stay on your device, with no server involvement
  • Protects a typical PDF in seconds, with no upload

Frequently Asked Questions

How to password protect a PDF?

Drop a PDF into PDFBook's Protect PDF tool, set a password, and download the encrypted copy. Everything happens in your browser, with no upload, no server, and no account required. Anyone opening the file will then need the password you chose.

How to encrypt a PDF for free?

PDFBook offers free PDF encryption using AES-256. The encryption happens entirely in your browser, so your password and document never leave your device. Just drop your PDF, set a password, and download the protected file.

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