How to create a Scroll Indicator

Step 1) Add HTML:

<div class=”header”>
<h2>Scroll Indicator</h2>
<div class=”progress-container”>
<div class=”progress-bar” id=”myBar”></div>
</div>
</div>

<div>content…</div>

Step 2) Add CSS:

/* Style the header: fixed position (always stay at the top) */
.header {
position: fixed;
top: 0;
z-index: 1;
width: 100%;
background-color: #f1f1f1;
}

/* The progress container (grey background) */
.progress-container {
width: 100%;
height: 8px;
background: #ccc;
}

/* The progress bar (scroll indicator) */
.progress-bar {
height: 8px;
background: #4caf50;
width: 0%;
}

Step 3) Add JavaScript:

// When the user scrolls the page, execute myFunction
window.onscroll = function() {myFunction()};

function myFunction() {
var winScroll = document.body.scrollTop || document.documentElement.scrollTop;
var height = document.documentElement.scrollHeight — document.documentElement.clientHeight;
var scrolled = (winScroll / height) * 100;
document.getElementById(“myBar”).style.width = scrolled + “%”;
}

See full working example: