How to Password Protect a PDF (Free, Without Uploading It)

Two kinds of PDF password

The PDF standard defines two different passwords, and it helps to know which one you need:

• Open password (user password). Required to open and view the document at all. With modern AES-256 encryption, the content is scrambled and is unreadable without it. This is what most people mean by a “password-protected PDF”.
• Permissions password (owner password). Controls what someone can do after opening the file — print, copy text, edit. These restrictions are honored by mainstream PDF readers, but they’re rules the software agrees to follow rather than hard protection. Determined users with the right tools can remove them.

So if the goal is confidentiality — only the right person should see this — the open password is what does the work. Permission settings are a polite “please don’t print or copy this” on top.

How to add a password, step by step

FaaTools Protect PDF encrypts the file with AES-256 directly in your browser. Neither the PDF nor the password is sent to a server, which matters for exactly the kinds of documents people want to protect.

1. Open Protect PDF and add your PDF.
2. Enter a password and type it again to confirm. The strength meter shows whether it’s weak, fair, good or strong — aim for strong.
3. Choose the permissions: Allow printing, Allow copying and Allow editing. Untick anything the recipient shouldn’t need to do.
4. Download the protected PDF and give it a clear name.
5. Open the downloaded file in your usual PDF reader and check that it asks for the password and opens correctly.

Choosing a password that actually protects the file

Encryption is only as strong as the password. AES-256 itself is not the weak point; short or guessable passwords are, because an attacker who has the file can try millions of guesses offline.

• Use at least 12–16 characters. Length matters more than symbols.
• Avoid names, birthdays, the document’s own title, and patterns like “Company2026!”.
• A passphrase of four or five random words is both strong and easy to read out over the phone.
• Use a different password for each document you send to different people.

The Password Generator can create a long random password in a click, also without anything leaving your browser.

How to share the password safely

The most common mistake is sending the password in the same email as the PDF. If that email is forwarded, intercepted or sent to the wrong address, the protection is gone. Instead:

• Send the file by email and the password by text message, phone call or a messaging app.
• Agree on a password in person beforehand for regular exchanges, such as with an accountant.
• Never put the password in the file name or the email subject line.

When to password protect a PDF

For ID documents, a visible watermark such as “Copy for ABC Lettings only — October 2026” makes a leaked copy much less useful to a fraudster. Add it with PDF Watermark before you encrypt the file.

What password protection can’t do

• It can’t stop someone who has the password from sharing the file or the password.
• It can’t stop a screenshot or a photo of the screen.
• Permission restrictions (no printing, no copying) can be bypassed by some software — rely on the open password for real confidentiality.
• It doesn’t hide the file’s existence or name, so keep file names neutral if that matters.