Put a password on a PDF before you send it
Sending something private over email or WhatsApp — a contract, a medical report, payroll — means it sits in an inbox anyone with that phone can open. Putting a password on the PDF means only the person you told the password to can read it. The encryption here is AES-256, the same standard banks use, and it is applied on your own device.
Anything you would not want read by whoever happens to pick up the recipient's phone: a signed contract, a medical report, payroll or salary details, a scan of an ID document, financial records going to an accountant.
Email and WhatsApp are convenient and not private. A message is forwarded, an account is shared, a phone is handed to a child to play a game. A password on the file means the document is still protected after it leaves your hands.
Not in the same message as the file. That protects nothing at all — anyone reading the email has both halves.
Send the file by email and the password by phone call or SMS, or agree it in person beforehand. For something you send to the same person regularly, agree one password once and reuse it rather than mailing a new one each time.
Pick something that is not guessable from the document itself. A contract protected with the client's own company name is not protected.
The encryption is AES-256 — the current standard, the same class of protection banks use, and not something anyone breaks by brute force. Which cuts both ways: a forgotten password cannot be recovered, by us or by anyone. Keep a copy of the original unlocked file somewhere safe.
The separate option to prevent printing and copying is weaker, and you should know that. It sets a flag that well-behaved PDF readers respect, but a determined person with the right software can ignore it. The password is the real protection; the restriction is a polite notice on top.
On your device, in this page. The file is not uploaded and neither is the password — which would rather defeat the point of encrypting a private document in the first place. If you need to remove the password later, Unlock PDF does that, also without uploading anything.
AES-256, which is the current standard and is not realistically breakable. That also means a forgotten password cannot be recovered by anyone, including us.
Separately from the file, and by a different route — if the PDF went by email, send the password by phone or message. Both in one email protects nothing.
Yes, there is an option for that. Be aware it is a polite restriction that most PDF readers honour, not a hard guarantee — the password is the real protection.
No. AES-256 has no back door, and we hold nothing that could help. Keep the original file and write the password down before you send the locked copy to anyone.
No. It is encrypted inside your browser on your own device.
Yes. Every normal PDF reader on Android and iPhone will ask for the password and then open it. So will Acrobat, Chrome and Preview.
This page uses one password for both. That covers what most people need.
No. Nothing is re-compressed; only encryption is added, so the file size barely changes.
Remove the old one first with Unlock PDF, then set the new one.
🔒 Everything on this page happens inside your browser. Your file is never uploaded to a server.