PDF Password Locker
Protect a PDF with a password required to open it. Check the password strength as you type and download an encrypted copy, all on your device.
Choose your PDF
Your PDF and password stay on your device. Processing happens locally with QPDF.
Drag & drop one PDF hereor choose a file from your device
Download PDFOne PDF, up to 200 MB.
About this tool
Uses AES-256 encryption. The filename ends in -locked.pdf. The original file on your device is unchanged. Modifying a digitally signed PDF invalidates its signature.
Can I replace an existing PDF password?
This tool rejects PDFs that are already encrypted. Use PDF Password Remover with the existing password first, then lock the unencrypted copy with your new password. Keep the new password somewhere you can retrieve it.