Protect a PDF with a password
Encrypt a PDF so it can only be opened with a password. Think about it: sending a confidential file to a stranger’s server to make it “secure” defeats the purpose. Here the encryption — standard PDF AES — happens on your own device.
How to use the Protect PDF tool
Select or drag the PDF to protect.
Type the password (and confirm it).
Click “Protect PDF” and download the encrypted file.
Your files stay on your device
This tool runs entirely in your browser using JavaScript and WebAssembly. There is no upload step and no server processing — open your network panel and check: zero document data is transmitted. It even keeps working offline once the page has loaded.
Frequently asked questions
How strong is the protection?
The file is encrypted with the PDF standard’s AES encryption. Without the password, the content is unreadable. The real weak point is always the password itself — use a long, unique one.
What if I forget the password?
There is no backdoor — that is what encryption means. Keep the password in a password manager. We cannot recover it because we never had it: it never left your browser.
What do the printing/copying restrictions do?
They set PDF permission flags that compliant viewers (Adobe Reader, browsers) enforce. They deter casual misuse, but only the open-password is cryptographic protection.
Is it safe to use this tool with confidential documents?
Yes — and verifiably so. PDFAgent has no upload step: your file is processed by JavaScript running in your own browser and never leaves your device. You can open your browser’s network panel (or even go offline after loading the page) and confirm that no document data is transmitted.