Quick answer
To password-protect a PDF, open a PDF encryption tool, add your file, enter a strong password and choose whether readers can print or copy text, then download the protected copy. Modern PDF encryption uses AES-256, and with a local tool the password and file never leave your device.
How do I add a password to a PDF?
- Open Protect PDF and drop in your file.
- Enter a password of at least 8 characters — longer is better.
- Choose permissions: Allow printing and Allow copying text.
- Click Protect PDF and download the encrypted copy.
- Send the password separately from the file, for example by text message.
What's the difference between an open password and permissions?
| Protection | What it does | How strong |
|---|---|---|
| Open password | Needed to open and read the file | Strong with AES-256 and a good password |
| Permissions | Limits printing, copying or editing | A courtesy; some apps ignore it |
An open password actually encrypts the file. Permission restrictions are respected by most viewers but aren't real security on their own.
How do I choose a strong PDF password?
- Use at least 12 characters, or a phrase of four or more random words.
- Don't reuse a password from your email or bank.
- Avoid names, birthdays and document titles.
How do I remove a password later?
If you know the password, open Remove password, enter it once and save an unlocked copy. To lift print or copy limits on a file you own, use Remove restrictions.
If you forget the open password of an AES-256 PDF, there is no practical way to recover it. Keep a copy somewhere safe.
Frequently asked questions
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