Password Protect PDF
Add a password to your PDF with AES-256 encryption. Your password and file never leave your device.
- Never leaves your device
- No limits
- No sign-up
- No watermark
Quick answer: To password protect a PDF, select the file, type the password twice and click "Protect PDF". The file is encrypted with AES-256 and only opens with the password. Everything happens in your browser: neither the password nor the document is uploaded.
How to do it in 3 steps
- 1Select the PDF.
- 2Type and confirm the password.
- 3Click Protect PDF and download the protected file.
Why use Pronto Arquivo
AES-256
The strongest standard in the PDF format, the same one Adobe Acrobat uses.
A password nobody sees
Since everything runs in your browser, the password never passes through a server.
Opens in any reader
Adobe Reader, browsers, phones: they all ask for the password and open normally.
Free, no sign-up
No file limits and no watermark.
Guides
How to share the password safely
Send the PDF through one channel (email) and the password through another (text message or a call). Anyone who intercepts one won't have the other.
Frequently asked questions
How do I put a password on a PDF?
Select the file, type the password twice and click "Protect PDF".
I forgot the password. Can you recover it?
No. The password is never sent or stored, so it can't be recovered. Keep it somewhere safe.
Can people with the password print and copy?
Yes. The protection prevents opening the file without the password.
Is it secure?
Yes. AES-256 encryption happens on your device; nothing is uploaded.