If I take a full-page screenshot of a Wikipedia page I get the whole page of text, including content that is not currently visible in the Firefox window. If I print the page to PDF, I also get all the content.
However, if a web page has CSS scrollbars then even a full-page screenshot is limited to what is visible in the window. Usually if I print the same page to PDF, I get all the content, but not always. Other scrolling mechanisms like iframes don’t work under any circumstances.
I can with effort identify and disable scrolling on individual
div boxes using Firefox’s inspection tools, but I have to do this every time and it’s very fiddly.
Is there any way to “flatten” an arbitrary web page so that I can take a full-page screenshot and get all the content?