Keep your PDF documents secure before sharing. Folium's Protect PDF tool adds security metadata and marks your document as protected — processed entirely in your browser, with no file upload to any server. Note: for full AES-256 encryption, a desktop application is required, as browser security restrictions prevent generating fully encrypted PDFs.
Marks the PDF with protection keywords and flags to signal restricted access.
The file is processed and returned in seconds with no server round-trip.
Your PDF stays on your device. Nothing is uploaded to any third-party server.
We tell you exactly what the tool does — metadata-level protection, not AES encryption.
Drop your PDF or click Choose File to select it.
Type a password to associate with the document's metadata.
Click Protect PDF. Your file is saved with protection metadata. For full encryption, use Adobe Acrobat or LibreOffice.
Add visual and metadata indicators that a document is intended to be password-protected.
Prepare documents with consistent metadata before applying full encryption in a desktop tool.
Mark PDFs that should not be redistributed before sending to internal stakeholders.
Protect draft documents from casual editing while noting they require review.
This tool processes your PDF entirely in your browser. The file is never uploaded to any server. We apply protection metadata flags using pdf-lib and return the file to your device. Because true password encryption (AES-128/256) requires low-level cryptographic PDF operations that browsers cannot perform securely, we are transparent that this tool applies metadata-level protection only.
Protect your PDF online for free with Folium — security metadata, private processing, no upload, no account. For full AES encryption, combine with LibreOffice or Adobe Acrobat. Free browser tool, always.