Protect PDF
Encrypt with AES-256 and a password, and limit printing or copying.
Keep sensitive documents safe. Set an open password, choose what readers are allowed to do, and download an AES-256 encrypted PDF.
How to password-protect a PDF
- Choose your PDF.
- Enter a password twice and set permissions.
- Click “Protect PDF” and download.
Frequently asked questions
What if I forget the password?
There is no way to recover it, so store it somewhere safe before sharing the file.
How strong is the encryption?
Files are encrypted with AES-256, the strongest standard PDF encryption.
How do I password protect a PDF?
Open the PDF, type a password twice and click “Protect PDF”. The downloaded copy is encrypted with AES-256 and asks for the password every time it is opened.
What is the difference between an open password and a permissions password?
An open password is needed to open and read the file at all. A permissions password controls actions such as printing, copying and editing in a file that can already be opened. For a confidential document, the open password is the one that matters.
Can I stop people printing or copying my PDF?
Yes. Set permissions to restrict printing, copying text, editing and other actions, protected by a separate permissions password. Pair it with an open password if the content itself is confidential.
How should I send the password?
By a different route from the file, for example a text message when the PDF goes by email, so that someone who intercepts one doesn’t get both.
Are my files uploaded to a server?
No. ModifyPDF processes files with JavaScript inside your browser. Your documents never leave your device, and nothing is stored after you close the page.
Strong encryption
Your PDF is encrypted with AES-256, the standard used by current PDF readers. A checklist shows whether your password meets common strength rules: length, upper and lower case, numbers and special characters.
Permissions
Optionally restrict printing, copying text, editing and other actions, protected by a separate permissions password. Keep your password safe: there is no way to recover it if it’s lost.
Two kinds of password
An open password (also called a user password) is needed to open and read the file. A permissions password (owner password) controls actions such as printing, copying and editing. For confidential documents, the open password is the one that matters.
Sharing a protected PDF
Send the password by a different channel from the file, for example by text message when the PDF goes by email, so someone who intercepts one doesn’t get both. Our guide to PDF passwords explains how PDF encryption works.