How to Detect a Mobile Device in jQuery

Use the JS matchMedia() Method

You can simply use the JavaScript window.matchMedia() method to detect a mobile device based on the CSS media query. This is the best and most reliable way to detected mobile devices.

The following example will show you how this method actually works:

<script>
$(document).ready(function(){
    if(window.matchMedia("(max-width: 767px)").matches){
        // The viewport is less than 768 pixels wide
        alert("This is a mobile device.");
    } else{
        // The viewport is at least 768 pixels wide
        alert("This is a tablet or desktop.");
    }
});
</script>