Is this real encryption?

Yes — AES encryption via the PDF standard's security handler, plus printing/copying/editing permissions. Not a soft lock.

What if I forget the password?

The file cannot be opened — by us or anyone. There is no backdoor; store the password safely.

No — encryption happens in your browser; the password never leaves your device.

Password-protect a PDF with AES encryption plus printing/copying permissions. The password never leaves your device.