How to protect a PDF with a password and how to unlock it
A contract, a bank statement, test results: a document sent by e-mail is worth protecting. PDF has built-in mechanisms for this, but they are easy to confuse.
Two kinds of PDF protection
The PDF specification has two independent passwords. An open password locks the whole document: without it you can’t see the content. A permissions password lets you open the file but restricts what can be done with it: printing, copying text, editing or adding annotations. For confidential data you always need an open password. Permission restrictions alone are more a polite request to programs than real protection, and some tools can bypass them.
How to protect a file in PDFowo
- Open the Protect PDF tool and add the document.
- Type a password. Choose a strong one: a dozen or more characters, ideally a phrase made of several words.
- Optionally tick restrictions, e.g. no printing, editing or copying.
- Download the protected file and check that it opens only with the password.
How to share the password safely
Never send the password in the same message as the file. It is best to use a different channel: a text message, a messaging app or a phone call. Avoid passwords like “1234”, a date of birth or the company name, because they are the first in the dictionaries used to crack protection.
How to remove the protection
If you have a password-protected file and know the password, the Unlock PDF tool removes it and the restrictions, so the document can be edited, merged or have its text copied. That is useful when, for example, the accounts department has sent a protected statement and you want to combine it with other documents. The tool is meant for files you have the right to, not for cracking someone else’s protection: without the open password you can’t unlock the document.
Privacy while protecting a file
Protecting a document with a password on someone else’s server is questionable: the file would have to leave your computer unencrypted. In PDFowo the encryption happens in your browser, so the document and the password never leave your computer.
Extra precautions
- A protected file doesn’t protect the content if the password falls into the wrong hands, so don’t keep it in a note next to the file.
- Keep an unprotected copy in a safe place so you don’t lose access if you forget the password. A forgotten open password cannot be recovered.
- Consider redacting sensitive passages if the recipient doesn’t need to see them at all.
Free, no sign-up. Your files stay on your device.
Open the Protect PDF tool →Passwords in practice: how to choose and remember one
A good file password is a sentence or a few unrelated words, for example “green-lamp-runs-past-window”. It is long, so hard to crack, and at the same time easier to remember than a random string of characters. If you protect many files, consider a password manager that generates and stores separate passwords.
Remember that a password protects a file only as long as the recipient, not bystanders, has it. If you send a document to several people, consider separate versions with different passwords: in case of a leak, you will know where it came from.
Frequently asked questions
Can a forgotten password be recovered?
No. An open password can’t be recovered, so keep an unprotected copy in a safe place.
Will every reader open a protected file?
Most popular PDF readers support standard passwords. Very old programs may have trouble with them.
Is a ban on printing or copying impossible to get around?
No. Typical readers respect permission restrictions, but some tools can bypass them. For confidential data, set an open password.
Is the document uploaded to a server while it is being protected?
No. The operation happens in your browser, so the file and the password never leave your computer.