Protect PDF — Add a Password to a PDF File
Add a password to a PDF so only the people you give it to can open it — sensible before emailing anything containing personal or financial information.
📖 New here? Read the step-by-step guide: How to Password Protect a PDF Free Online
How to use Protect PDF
- Upload the PDFChoose the document you want to protect, up to 25 MB.
- Choose a passwordPick something strong. If you cannot think of one, the password generator on this site will make one for you.
- Download the protected fileThe encrypted PDF now asks for that password whenever anyone opens it.
What the encryption actually is
The file is encrypted with AES-256 using qpdf — the current PDF encryption standard, supported by every modern PDF reader. This is real cryptography, not a viewing restriction that any tool can strip off. Without the password the contents cannot be read.
Send the password separately
The most common mistake is emailing the protected PDF and its password in the same message, which protects nothing at all. Send the password by another route — a phone call, a text message, a different app. That single habit is what makes PDF encryption worth doing.
There is no recovery
If you lose the password, the document cannot be opened. We cannot recover it, and neither can anyone else — that is what AES-256 means. Store the password somewhere reliable before you send the file anywhere, and keep an unprotected original for yourself.
When this is worth doing
Anything with identity details, bank information, medical records or salary data that has to travel by email deserves a password. Email itself provides no protection once a message has left your outbox.
Questions people ask
What encryption is used?
AES-256, applied with qpdf. It is the current PDF standard and is supported by every modern PDF reader.
Can I remove the password later?
Yes — use the Unlock PDF tool with the password you set.
What happens if I forget the password?
The file cannot be opened by anyone, including us. Keep the password somewhere safe and hold on to an unprotected original.
PDF pe password kaise lagaye?
Protect PDF kholo, PDF choose karo aur password likho — AES-256 se locked PDF download hogi. File lock hote hi server se delete ho jati hai.