All tools / Edit and organise PDF
Protect PDF
Lock a PDF with a password (AES-256 encryption).
Drop files here
Accepts PDF
How to use Protect PDF
- Drop your PDF file onto the page, or choose it from your device.
- Set the options you need, then press the button to start.
- Download the result. The whole job happens in your browser; nothing is uploaded.
Good to know
The file is encrypted with AES-256, so it cannot be opened without the password. Because everything happens on your device, the password is never transmitted. Keep it safe: nobody, including us, can recover a forgotten one.
Questions and answers
Is Protect PDF really free?
Yes. There is no charge, no account and no limit on how many files you convert.
Are my files uploaded anywhere?
No. The conversion runs inside your browser, on your own device. Your files are never sent to us or to anyone else.
Is there a file-size limit?
There is no fixed limit. Very large files depend on how much memory your device has; a computer copes with more than a phone.
Does it work without an internet connection?
Yes, once you have opened the tool while online. You can also save the whole site for offline use from the home page.