Cross-Browser Method to Determine Vertical Scroll Percentage in Javascript
How Can I Find out What Percentage of the Vertical Scrollbar a User Has Moved Through at Any Given Point? It's Easy Enough to Trap the Onscroll Event to Fire...
How can I find out what percentage of the vertical scrollbar a user has moved through at any given point?
It's easy enough to trap the onscroll event to fire when the user scrolls down the page, but how do I find out within that event how far they have scrolled? In this case, the percentage particularly is what's important. I'm not particularly worried about a solution for IE6.
Do any of the major frameworks (Dojo, jQuery, Prototype, Mootools) expose this in a simple cross-browser compatible way?
13 Answers
Oct 2016: Fixed. Parentheses in jsbin demo were missing from answer. Oops.
Chrome, Firefox, IE9+. Live Demo on jsbin
var h = document.documentElement,
b = document.body,
st = 'scrollTop',
sh = 'scrollHeight';
var percent = (h[st]||b[st]) / ((h[sh]||b[sh]) - h.clientHeight) * 100;
As function:
function getScrollPercent() {
var h = document.documentElement,
b = document.body,
st = 'scrollTop',
sh = 'scrollHeight';
return (h[st]||b[st]) / ((h[sh]||b[sh]) - h.clientHeight) * 100;
}
Elena Rostova holds a Master's degree in Public Health Journalism. She covers groundbreaking medical research, holistic wellness trends, mental health awareness, and nutritional science.
