Use the maxWidth property in JavaScript to set the maximum width.
Example
You can try to run the following code to set the maximum width of an element with JavaScript −
<!DOCTYPE html>
<html>
<body>
<p>Click below to set Maximum width.</p>
<button type="button" onclick="display()">Max Width</button>
<div id="box">
<p>This is a div. This is a div. This is a div.</p>
<p>This is a div. This is a div. This is a div.</p>
<p>This is a div. This is a div. This is a div.</p>
<p>This is a div. This is a div. This is a div.</p>
<p>This is a div. This is a div. This is a div.</p>
</div>
<br>
<script>
function display() {
document.getElementById("box").style.maxWidth = "80px";
}
</script>
</body>
</html>