Add a password to a PDF with AES-256 encryption, and choose whether readers may print, copy or edit it. Encryption happens in your browser, so neither the file nor the password is uploaded, and there's no size limit or sign-up.
How to use Protect PDF
Choose a PDF to protect.
Type the Password to open, then Repeat password.
Optionally set an Owner password and the Permissions for printing, copying, editing and comments.
Click Protect PDF and download the encrypted file.
Frequently asked questions
How do I put a password on a PDF?
Open the PDF, enter a password twice, and click Protect PDF. Anyone opening the downloaded file will be asked for that password.
What encryption does it use?
AES-256, the strongest encryption PDF supports, applied by qpdf running in your browser. The file is checked after encrypting to make sure it really asks for the password.
What is an owner password?
It controls the permissions, such as printing and copying, and is needed to change them. If you restrict anything and leave it empty, a long random owner password is set for you, so the restrictions can't be lifted with the open password. If you don't restrict anything and leave it empty, the owner password is the same as the open password.
How strong are the print and copy restrictions?
The open password is real encryption: without it, the file can't be read. Permissions are different: standard readers respect them, but tools such as Unlock PDF can remove them from a file that opens. Use them to discourage copying, not to secure content.
What if I forget the password?
It can't be recovered, by this tool or by us, since nothing is stored. Keep a copy of the unprotected file or the password somewhere safe.
Can I protect a PDF that already has a password?
Remove the old password with Unlock PDF first, then set the new one here.
Is it safe to encrypt a PDF online?
Here the file and password never leave your device: encryption happens in your browser, so nothing is uploaded.
Permissions you can set
Choose a password of at least 12 characters that isn't used elsewhere, and send it by a different channel from the file, for example the PDF by email and the password by text message. Make your final edits, compress and watermark the PDF first, since most tools need the password removed to change it later.
Permission
Options
Printing
Allowed, Low quality, or Not allowed
Copying text and images
Allowed or not
Editing (changing content, adding or removing pages)