PDF Protect

Encrypt a PDF with password protection. Set permissions for printing, copying, and editing.

PDF Protect tool

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Example

Input: A 5-page PDF, user password open123, a different owner password, printing allowed, copying off

Result: <file>-protected.pdf encrypted with AES-256: it asks for a password to open, and the owner password can lift restrictions

Encryption uses the PDF Standard Security Handler (revision 6) with AES-256 in your browser. Using the same user and owner password is refused.

PDF Protect Permission Settings

SettingDefaultWhat it covers
Allow PrintingOnPrinting, including high quality
Allow CopyingOffCopying text and images
Allow ModifyingOffEditing, comments, page assembly
Filling form fieldsAlways onExisting form fields only
Screen reader accessAlways onText extraction for accessibility

Permissions are enforced by the PDF reader; the open password is enforced by encryption.

  1. Upload the PDF file you want to protect with a password.
  2. Enter an owner password (required - it controls the permissions) and, optionally, a user password that must be entered to open the document.
  3. Configure the permission options to allow or restrict printing, text copying, and document editing.
  4. Review your password and permission settings to ensure they match your security requirements.
  5. Click "Protect PDF" to encrypt the document with the specified passwords and permissions.
  6. Download the password-protected PDF and store your password in a safe place, as it cannot be recovered.

Password Protecting a PDF With AES-256

PDF Protect adds a password to a PDF and encrypts it with AES-256, the strongest method in the PDF standard. You can require a password to open the file, limit printing, copying and editing, or both.

PDF security uses two passwords. The user password, also called the open password, is needed to view the document. It is optional. The owner password is required. It lets its holder change the permissions or remove the protection. The two must be different, because anyone who could open the file could otherwise also lift the limits.

The permissions are three switches. Allow Printing is on by default. Allow Copying and Allow Modifying are off. Two things always stay allowed: filling in existing form fields, and text access for screen readers. The protected PDF opens in Adobe Acrobat, Chrome, Firefox, Apple Preview and other up-to-date readers.

Know what each part really does. The open password is true encryption, and with a long password the content cannot be read without it. Permission limits are different. They rely on the PDF reader to honor them, and some programs ignore them. Treat them as a polite barrier, not a guarantee.

Encryption happens in your browser, using pdf-lib and the Web Crypto API. Your file and passwords are never sent anywhere or stored. That also means a lost password cannot be recovered, so keep it safe. A file that is already protected must be unlocked first with PDF Unlock. For a strong password, try the Password Generator.

Sources

Frequently Asked Questions

The user password (open password) must be entered to view the document at all. The owner password controls permissions such as printing, copying and editing, and lets its holder remove the protection. The owner password is required here, while the user password is optional. The two must be different.
Leave the user password empty and set only an owner password. Keep Allow Copying off. Anyone can then open and read the file, but PDF readers that follow the standard will block text copying. Be aware that some programs ignore these permission flags, so do not rely on them for secrets.
AES-256 itself is not known to be breakable in practice. The weak point is the password. A short or common open password can be guessed by cracking software that tries millions of options. Use a long passphrase or a random password of 12 or more characters for anything sensitive.
It cannot be recovered. The password is used only while the file is encrypted in your browser, and it is never stored or sent anywhere. Without it, the protected file cannot be opened or unlocked, so keep your original unprotected copy or save the password in a password manager.
Yes, in current readers. The file uses the AES-256 method from the PDF standard, which Adobe Acrobat, the viewers in Chrome and Firefox, Apple Preview and most modern apps support. Very old PDF software from before this method existed may not open it.

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