How to check if the bottom of a page is in the viewport?
const getBottomVisiblity = () =>
document.documentElement.clientHeight + window.scrollY >=
(document.documentElement.scrollHeight || document.documentElement.clientHeight)
// output: true
getBottomVisiblity()
October 1st, 2019
Returns true if the document height plus the currently scrolled pixel number is larger/equal to the document's content height or rather document height.
Apply that function to a scroll event listener and you can always check if the page bottom is visible.