Use the paddingLeft property in JavaScript to set the left padding. You can try to run the following code to return the left padding of an element with JavaScript −
Example
<!DOCTYPE html>
<html>
<head>
<style>
#box {
border: 2px solid #FF0000;
width: 150px;
height: 70px;
}
</style>
</head>
<body>
<div id = "box">This is demo text.</div>
<br><br>
<button type = "button" onclick = "display()">Left padding</button>
<script>
function display() {
document.getElementById("box").style.paddingLeft = "100px";
}
</script>
</body>
</html>