JavaScript – Change the Font Weight of HTML Element

To change the font weight of a HTML Element using JavaScript, get reference to this HTML Element element, and assign required font weight value to the element.style.fontWeight property.

In the following example, we will change the font weight of HTML Element with id "myElement" to "600", in JavaScript, using element.style.fontWeight property.

example.html

<!DOCTYPE html>
<html lang="en">
<head>
    <style>
        #myElement {
            border:1px solid #CCC;
            width:100px;
            height:100px;
        }
    </style>
    <meta charset="utf-8">
</head> 
<body>
    <h2>Change Font Weight of HTML Element in JavaScript</h2>
    <div id="myElement">Hello World!</div>
    <br>
    <button type="button" onclick="changeStyle()">Click Me</button>
    <script>
    function changeStyle(){
        var element = document.getElementById("myElement");
        element.style.fontWeight = "600";
    }
    </script>
</body>
</html>
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Conclusion

In this JavaScript Tutorial, we learned how to change the font weight of a HTML Element using JavaScript.