Protect PDF files such as bank statements, salary slips and ID documents with a password before sending them. Only people who know the password can open the PDF, and the encryption happens on your device, so neither the file nor the password goes anywhere. You can add watermark to PDF copies as well, or compress PDF files first so they fit in an email.
How to protect PDF
- Select the PDF.
- Type a password and type it again to confirm.
- Tap “Protect PDF” to encrypt PDF with AES-256.
- Download the protected PDF and share the password separately, for example by phone.
Tips for best results
- Choose a password that is easy to say over the phone but hard to guess, such as three unrelated words with a number.
- Compress, merge or sign the PDF before protecting it: most PDF tools cannot edit a file that is already encrypted.
- Keep an unprotected copy on your own device, so you are never locked out of your own document.
Frequently asked questions
How strong is the protection?
The PDF is encrypted with AES-256 by qpdf, a widely used open-source PDF tool. Strength then depends on your password: use at least 8–10 characters mixing words and numbers, not your date of birth or phone number.
What if I forget the password?
It cannot be recovered, by us or anyone else, because we never see it. Keep your original unprotected file, or note the password somewhere safe.
Can I stop people from printing or copying?
This tool adds an open password, which is the real protection. Print and copy restrictions in PDFs are easily ignored by many apps, so we don't offer them as if they were secure.
Will the PDF open on phones and in all readers?
Yes. AES-256 is supported by Adobe Reader, Chrome, Edge, Firefox, iPhone and Android PDF viewers, which all ask for the password when opening.
Should I send the password in the same email?
No. Anyone who gets the email would then have both. Share the password by a different route, such as a phone call or a separate message.
Related tools
- Unlock PDFRemove the password from your PDF when you know it.
- Add Watermark to PDFStamp text like CONFIDENTIAL on every page, in any language.
- Compress PDFReduce PDF size losslessly or to any target in KB or MB.
- Merge PDFCombine several PDF files into one, in any order.
- Sign PDFDraw or upload your signature and place it on a PDF.