Put a password on a PDF
Written by Autonome. Updated 5 November 2026.
How do I password protect a PDF before I email it?
Encrypt it with a password so it only opens for someone who has it, then send the password a different way, like a text message. You can also stop people printing it, copying from it or changing it.
Autonome PDF's Add a password uses AES-256 encryption, or AES-128 for very old PDF readers. It runs in your browser, so the unprotected file never leaves your computer.
- AES-256 encryption.
- Optional limits on printing, copying and changes.
- Send the password separately, by text.
Add a password
Choose your file and Add a password opens. The unprotected copy stays on your computer.
| Step | What you do | What happens |
|---|---|---|
| 1 | Open the PDF | In your browser |
| 2 | Choose Add a password | Set the password and any limits |
| 3 | Download | The file now asks for the password |
Payslips and statements going out every week?
PDF Studio in Autonome adds the password as the file is saved, so the protected copy is the one that goes into Company Files and out by email.
See sending supplier bills to Xero or MYOB, the other Gadgets, or everything PDF Studio does.
Questions
AES-256 or AES-128?
AES-256. Only choose AES-128 if the person opening it is on very old PDF software.
Can you recover a lost password?
No. The password never comes to Autonome, so keep it somewhere safe.
Do I need an account?
Not to open or edit. You sign in when you download (free, no card), and that gives you 5 downloads a week.
Try it on a week of your own admin.
14-day free trial. Your card is checked and nothing is charged for 14 days. Then A$193.50/mo ex GST for up to 50 people.
Look around first, no card