Firebug and google console both does not let change content rendered through pdf.js why ? and how?

Question

One can not change content (DOM elements) rendered through pdf.js using firebug and google. How pdf.js achieve this, how can I do the same in my html page

Answer 1

PDF.js renders its output into different <canvas> elements (one per page). You can see a small preview of the canvas when using the Firefox DevTools:

It still generates DOM elements, though, to allow interacting with the contents, i.e. selecting and copying them.