How to password protect a PDF
Protect PDF encrypts your document with an open password: without it, the file cannot be read. It is the right protection when you email or upload to the cloud a payslip, a contract, a medical report or anything with personal data.
You can protect several PDFs at once with the same password and download them together in a ZIP.
Step by step
- Upload the PDF you want to protect (or several).
- Enter the new password, at least 8 characters long.
- Process and download the encrypted PDF.
- Share the password through a different channel from the file, for example by phone or text if the PDF goes by email.
What kind of protection is applied
The document is encrypted with 256-bit AES, the strongest algorithm in the PDF standard, which Adobe Reader, browsers and mobile viewers open without trouble. Unlike 'no printing' or 'no copying' restrictions, which many apps ignore, an open password genuinely encrypts the content.
The password is not stored anywhere. If you forget it, nobody can recover it for you, so save it in your password manager before deleting the original.
Choosing a good password
The strength of the encryption depends almost entirely on the password. Eight characters is the minimum; a passphrase of several words or a long password from a password manager is far harder to guess. Avoid birthdays, ID numbers or your company name.
Protect the PDF as the last step: an encrypted file has to be unlocked before it can be merged, compressed or edited. In a workflow you can make 'protect with password' the final step; for safety, passwords are never saved in recipes.
Frequently asked questions
- How long does the password need to be?
- At least 8 characters. Longer is better.
- What encryption does it use?
- 256-bit AES, supported by all common PDF readers.
- Can I recover the password if I forget it?
- No. It is not stored anywhere. Keep an unprotected copy or write the password down somewhere safe.
- Can I protect several PDFs with the same password?
- Yes. Upload them together and you get them all encrypted in a ZIP.
- How do I remove the password later?
- Use Unlock PDF and enter the password you set.