Keep a PDF private with a password
A password-protected PDF is encrypted: without the password, its contents are unreadable, whether it is attached to an email, saved in the cloud or copied to a USB stick. This tool uses AES-256, the strongest encryption the PDF format offers, and it works in your browser, so the unprotected file is never uploaded anywhere.
Permissions
- Print it — allow or block printing.
- Copy its text — allow or block selecting and copying text and images.
- Change it — allow or block editing, comments, form filling and adding or removing pages.
- Permissions are respected by Adobe Acrobat, browsers and most PDF readers, but they are a request rather than a lock: the password to open the file is what truly protects it.
How to protect a PDF
- Drop your PDF.
- Choose a password and type it twice. A long password with a mix of words and numbers is safest.
- Choose the permissions, then press Protect PDF and download the protected copy.
Good to know
- There is no way to recover a forgotten password — keep it somewhere safe, such as a password manager.
- Send the password separately from the file, for example by SMS when you email the PDF.
- Without an owner password, a random one is set, so the permissions cannot be lifted by someone who only knows the password to open it.
Frequently asked questions
How strong is the protection?
The file is encrypted with AES-256. With a strong password, it cannot be opened by guessing in any practical amount of time. Short or common passwords can be guessed, so use a long one.
Can I remove the password later?
Yes. Use Unlock PDF with the password to save a copy without it.
Is my PDF uploaded?
No. Encryption runs in your browser; only the encryption program is downloaded the first time you use it.