[removed] How to detect if browser window is scrolled to bottom?

Question

I need to detect if a user is scrolled to the bottom of a page. If they are at the bottom of the page, when I add new content to the bottom, I will automatically scroll them

Answer 1

You can check if the combined result of the window's height and scroll top is bigger than that of the body

if (window.innerHeight + window.scrollY >= document.body.scrollHeight) {}

Answer 2

Using defaultView and documentElement with functional code snippet embedded:

const { defaultView } = document;
const { documentElement } = document;
const handler = evt => requestAnimationFrame(() => {
  const hitBottom = (() => (defaultView.innerHeight + defaultView.pageYOffset) >= documentElement.offsetHeight)();
  hitBottom
    ? console.log('yep')
    : console.log('nope')
});
document.addEventListener('scroll', handler);

<pre style="height:110vh;background-color:fuchsia">scroll down</pre>

Answer 3

The accepted answer did not work for me. This did:

const element = document.createElement('div');
document.body.appendChild(element);
document.addEventListener('scroll', () => {
    const viewportHeight = window.innerHeight;
    const distance = element.getBoundingClientRect().top;
    if (Math.floor(distance) <= viewportHeight) {
        console.log('yep')
    } else {
        console.log('nope')
    }
})

Answer 4

window.onscroll = function(ev) {
    if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight) {
        // you're at the bottom of the page
    }
};

See demo

Answer 5

You can look into jquery's infinite scroll:

http://www.infinite-scroll.com/infinite-scroll-jquery-plugin/

Which sounds like it does what you're asking for, assuming you're willing to use the jquery library and not hoping for a strict pure JS method.

Answer 6

const handleScroll = () => {
    if (Math.round(window.scrollY + window.innerHeight) >= Math.round(document.body.scrollHeight)) {
        onScroll();
    }
};

This code worked for me in Firefox and IE as well.