How to use it
- Add your PDF
- Type a password twice
- Download the protected PDF
Questions people ask
How strong is the protection?
It uses AES-256, the strongest encryption PDF supports. Choose a long password that is hard to guess.
What if I forget the password?
Nobody can open the file without it, not even us, because we never see it. Keep it safe.
Is Protect PDF really free?
Yes. Every PDFtoOne tool is free with no login, no daily limit and no watermark. The site is supported by ads.
Is there a file size limit?
We set no limit. Files are processed by your own device, so the only limit is its memory. Computers handle very large files; phones handle most everyday files easily.
Does it work offline?
Yes. Once you have used a tool, it keeps working without internet. You can also install PDFtoOne as an app.