How to password-protect a sensitive pdf document
- Step 1Upload the PDF to protect — Drop the sensitive document into the password protect tool.
- Step 2Set a strong password — Use at least 12 characters with uppercase, numbers, and symbols.
- Step 3Encrypt the PDF — The tool applies AES-256 encryption with your password.
- Step 4Share the protected PDF and password separately — Send the PDF by email and the password via a different channel (SMS, phone call).
Frequently asked questions
What encryption strength does this tool use?+
AES-256 — the same encryption standard used by banking and government systems.
Should I send the password in the same email as the PDF?+
Never. Send the PDF by email and communicate the password via SMS, phone, or a separate secure message.
Can recipients open the PDF on a phone?+
Yes — password-protected PDFs are supported by iOS Files app, Android PDF viewers, and all standard PDF readers.
Privacy first
All PDF processing runs locally in your browser using PDF-lib and pdf.js. No file is ever uploaded — only metadata counters are saved for signed-in dashboard stats.