I want to be honest and open here: I did not write the PDF parser on my own. I heavily relied on the PDF.js project from Mozilla. I have a disclosure in the footer, but perhaps I should communicate about it more clearly.

No, it was clear already from the webpage that it uses PDF.js. I've also used it. I just think this is a really great way of visualizing PDF's, I shared it with my team as we deal with them a lot.