Protect PDF
Add a password to a PDF with AES-256 encryption. Free, with no sign-up.
This tool uses our server. Your file is sent over an encrypted connection, processed, and deleted as soon as the result comes back. It is never stored or shared. How files are handled
Protect PDF locks a PDF with a password, so it can't be opened without it. Use it before emailing bank statements, payslips, ID documents or contracts. The PDF is encrypted with AES-256, the strongest encryption PDF readers support, and opens normally in Acrobat, browsers and phone apps once the password is entered. Choose a password of at least six characters and keep it safe: nobody can recover it. The encryption runs with qpdf on our server; the file and the password are deleted right after.
How to use Protect PDF
- 1
Choose your PDF
Drop or choose a PDF up to 30 MB.
- 2
Set a password
Type it twice; use at least six characters.
- 3
Protect and download
Save the locked PDF and keep the password somewhere safe.
What it does
- AES-256 encryption
- The strongest PDF encryption, supported by all modern readers.
- Opens everywhere
- Acrobat, browsers and phone apps ask for the password.
- Password never stored
- It is used once to encrypt the file, then discarded.
- Free
- No sign-up and no watermark.
Questions
What if I forget the password?
It can't be recovered, by us or anyone else. Keep a copy of the unprotected original, or store the password somewhere safe.
Can I remove the password later?
Yes. Use Unlock PDF with the correct password.
Is my file uploaded?
Yes. This tool needs our server, so the file is sent over an encrypted connection, processed, and deleted as soon as the result is sent back. It is never stored, shared or looked at. Most other tools on this site run entirely in your browser.
Is there a size limit?
Files can be up to 30 MB. Very large or complex files can take up to a couple of minutes.