How to convert PDF to password-protected PDF – Protect PDF online
- Upload – click “Choose files” or drag your PDF file into the box above (.pdf).
- Adjust settings – optionally choose image quality.
- Convert – press the button; Kitbly processes your file on a secure server in seconds.
- Download – save your password-protected PDF. The file is deleted from our servers automatically after 1 hour.
About Protect PDF
Lock a PDF with a password before you email or upload it. Kitbly encrypts the whole file with AES-256 – the standard used by Adobe Acrobat – so it can only be opened by someone who knows the password. Printing and copying stay allowed for whoever opens it. The password is used once to encrypt the file and is never stored or logged.
Frequently asked questions
How strong is the protection?
AES-256, the strongest encryption in the PDF standard. Use a long password (12+ characters) – a short password is the weak point.
What if I forget the password?
Nobody can recover it – not even us. Keep a copy of the original or write the password down.
Will it open on phones?
Yes. Every modern PDF viewer (Adobe, Chrome, Edge, Safari, iPhone and Android) asks for the password and opens it.
Is Protect PDF free?
Yes – completely free, with no account, no daily limit and no watermark.
Are my files safe?
Files are sent over an encrypted HTTPS connection, processed automatically by our servers, never shared and permanently deleted after 1 hour. Nobody looks at your documents.
Do I need to install software or sign up?
No. It works in any browser on Windows, Mac, iPhone and Android. No account needed.
Is there a watermark?
Never. Your converted files are clean, with no watermark or branding.