When you need to securely share a PDF — whether it contains financial data, personal information, legal documents, or confidential business materials — simply attaching it to an email is not enough. There are three complementary techniques you can use to protect your documents: password encryption, redaction, and watermarking. Each addresses a different risk, and combining them gives you the strongest protection.
1. Password protection — control who can open it
The Password Protect tool encrypts your PDF with AES-256, the same encryption standard used by banks and governments. Anyone who receives the file will need the password to open it. This is the most fundamental layer of protection — if the file is intercepted, forwarded, or accidentally sent to the wrong person, its contents remain unreadable without the password.
Practical tips for password protection:
- Use a strong password — at least 12 characters with mixed case, numbers, and symbols.
- Share the password through a different channel than the document. If you email the PDF, send the password via text message or a phone call.
- Do not include the password in the same email as the attachment.
2. Redaction — permanently remove sensitive content
Password protection prevents unauthorized access, but what about the authorized recipient? If your document contains information that the recipient should not see — social security numbers, financial account details, personal addresses, or confidential names — you need to remove that content before sharing.
The Redact tool permanently removes text from the PDF. Unlike simply placing a black rectangle over text (which can be removed), redaction actually deletes the underlying content. The tool lets you search for specific text, email addresses, phone numbers, and other patterns, review what will be removed with a highlighted preview, and then apply the redaction permanently.
This is especially important for legal discovery, FOIA responses, medical records, and any situation where certain information must be withheld while the rest of the document is shared.
3. Watermarking — track and deter unauthorized sharing
A watermark does not prevent someone from reading the document, but it serves two purposes: it deters unauthorized redistribution (people are less likely to share a document stamped with "Confidential" or their name), and it helps you identify the source if a document leaks.
You can add text watermarks like "Confidential", "Draft", or the recipient's name. Image watermarks work well for company logos or official stamps. The opacity control lets you make the watermark visible enough to serve its purpose without interfering with readability.
Combining techniques for maximum security
For the highest level of protection, use all three techniques together:
- First, redact any sensitive information that the recipient should not see.
- Then, add a watermark with the recipient's name or "Confidential" marking.
- Finally, encrypt with a strong password.
This order matters. Redact first because you cannot search and redact text in an encrypted PDF. Add the watermark before encryption so it becomes part of the encrypted content and cannot be easily removed.
What about "print restriction" and "copy restriction"?
Some PDF tools offer restrictions that prevent printing or copying text. These are enforced by PDF viewer software and can be trivially bypassed — they offer no real security. AES-256 encryption with a strong password is the only effective technical protection against unauthorized access.
Privacy on our end
All files processed through PDF Tools are automatically deleted within 15 minutes. Your passwords are never logged or stored. The encryption happens on the server and the result is returned directly to you.