Add a password in three steps
- Open Protect PDF and select your file.
- Type a password twice. Optionally check Also prevent editing and copying.
- Click Protect PDF and download the encrypted file.
How strong is the protection?
Helpdf uses AES-256 encryption, the standard used by banks and governments. Without the password, the content of the file cannot be read. The strength of the protection therefore depends mostly on the password you choose.
Choosing a good password
- At least 10 characters, ideally a short sentence that is easy to remember.
- Avoid dates of birth, first names and the name of the company.
- Use a different password for each recipient or file when possible.
How to share the password
Never send the password in the same email as the file. Send it by SMS, give it by phone or agree on it in advance. That way, someone who intercepts the email still cannot open the document.
Removing a password
If you know the password and are tired of typing it, Unlock PDF creates an unprotected copy. Helpdf cannot open a PDF whose password you do not know — that is exactly what makes encryption useful.
Password or redaction?
A password protects the whole document. If you need to share a document but hide some information inside it — an account number, an address — use Redact PDF: the hidden text is permanently removed.