Protect PDF with Password
Add a password to a PDF online for free, with AES-256 encryption and optional print and copy restrictions. It runs in your browser; nothing is uploaded.
What it does
This tool encrypts a PDF so that it only opens with the password you choose. It uses AES-256, the strongest encryption in the PDF standard, supported by every current PDF reader. You can also restrict printing, copying and editing. The encryption is done by qpdf, a widely used open-source PDF tool, running in your own browser: the file and the password never leave your device. Before the download, the new PDF is opened as a PDF reader would open it, to confirm that it asks for the password and that all the pages are there.
How to use it
- Choose the PDF you want to protect.
- Type the password twice and, if you want, untick what should not be allowed.
- Press Protect PDF. The protected copy is downloaded; your original file is not changed.
Frequently asked questions
Is my PDF or my password sent anywhere?
No. Everything happens in your browser. The PDF and the password are not uploaded or stored, so the tool is safe for confidential documents.
How secure is the protection?
The file is encrypted with AES-256, which cannot be broken directly. The weak point is the password: a short or common one can be found by trying many combinations. Use a long password, for example several unrelated words.
What if I forget the password?
The PDF cannot be opened without it, and there is no way to recover it. Keep your original file or store the password in a password manager.
What is the difference between the password and the restrictions?
The password is needed to open the file at all. Restrictions only apply after it is opened and ask the reader program not to allow printing, copying or editing. Most readers respect them, but they are not real protection against a determined person.