JavaScript Change the Opacity of Div

To change the opacity of a div using JavaScript, get reference to the div element, and assign required opacity value to the element.style.opacity property.

Opacity value ranges from 0 to 1. For example, 0.2, 0.3, 0.8, 0.45, etc., are some of the values that can be assigned to opacity property.

Example

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
</head> 
<body>
    <h2>Change Opacity of Div in JavaScript</h2>
    <div id="myDiv">
        <p>This is a paragraph in Div.</p>
        <span>This is a span in Div.</span>
    </div>
    <br>
    <button type="button" onclick="changeStyle()">Click Me</button>
    <script>
    function changeStyle(){
        var element = document.getElementById("myDiv");
        element.style.opacity = "0.2";
    }
    </script>
</body>
</html>

Conclusion

In this JavaScript Tutorial, we learned how to change the opacity of a div using JavaScript.