JSFiddle - React, Tailwind, and code Playground

JavaScript

var isMobile = {
Android: function() {
    return navigator.userAgent.match(/Android/i);
},
BlackBerry: function() {
    return navigator.userAgent.match(/BlackBerry/i);
},
iOS: function() {
    return navigator.userAgent.match(/iPhone|iPad|iPod/i);
},
Opera: function() {
    return navigator.userAgent.match(/Opera Mini/i);
},
Windows: function() {
    return navigator.userAgent.match(/IEMobile/i);
    },
any: function() {
    return (isMobile.Android() || isMobile.BlackBerry() || isMobile.iOS() || isMobile.Opera() || isMobile.Windows());
    }
};

if(isMobile.any()) {
   alert('Device is a mobile');
} else{
   alert('Device is NOT a mobile');
}