EDIT in 2022 It might also be interesting to look at Intersection Observer that is now available in most browsers, and there is also a polyfill. const observer = new IntersectionObserver((entries, observer) => { entries.forEach((entry) => { let isVisible=(entry.intersectionRatio===1); }); }, {threshold:1}); observer.observe(document.querySelector(‘#element’); END EDIT I have this specific need that is to trigger an […]