How to password protect a PDF
Encrypt a PDF so it cannot be opened without a password — and understand exactly what that password does and does not protect.
Password-protecting a PDF is what you do before a document travels somewhere you do not control: an email thread that gets forwarded, a shared drive, a messaging app. Without the password the file is unreadable, whoever ends up with it.
Add a password
Upload the PDF
Drop in the document you want to encrypt.
Set a password
Enter it, then confirm it. Pick something you will not lose — see below.
Protect
Click Protect PDF. The encrypted file downloads immediately.
If you forget it, it is gone
There is no reset link, and that is by design rather than an oversight. Your password never reaches us — the encryption happens in your browser, so there is nothing on any server to reset it from. A forgotten password means a permanently unreadable document. Put it in a password manager before you send the file.
What the password actually protects
It protects the file, not the information. The password is required to open the document at all — but anyone you give it to can open the file and save an unprotected copy. Encryption stops the wrong person reading it in transit; it does not bind the right person to secrecy afterwards.
It is also worth separating this from a watermark. A watermark marks a document as confidential; a password stops it being read. They solve different problems, and a watermark is trivially removable.
Removing a password later
If you know the password and the constant retyping has become the problem, Unlock PDF produces a copy that opens freely. It removes a password you have — it cannot recover one you have lost, and no honest tool can.