JSFiddle - React, Tailwind, and code Playground

JavaScript

function detectDevice(s) {
    var userAgent = navigator.userAgent.toLowerCase(),
        platform = navigator.platform.toLowerCase();
    if (s) {
        if (userAgent.match(s.toLowerCase()) != null)
            return true;
        return false;
    }
    
    this.isSmall = function() {
        if (screen.width <= 480 && screen.height <= 480)
            return true;
        return false;
    };
    this.device = function() {
        
        var a = ["Android", "iPhone", "iPad", "iPod", "BB", "webOS"];
        for (var i = 0; i < a.length; i++) {
            if (userAgent.match(a[i].toLowerCase()) != null)
                return a[i];
        }
        var a = ["Win", "Mac", "Linux"];
        for (var i = 0; i < a.length; i++) {
            if (platform.match(a[i].toLowerCase()) != null)
                return (a[i] == "Win") ? "Windows" : a[i];
        }
        return "Unknown Device";
    };
    this.userAgent = userAgent;
    this.platform = platform;
}
var device = new detectDevice();
document.body.innerHTML += "Is small: " + device.isSmall() + "<br />";
document.body.innerHTML += "Device: " + device.device() + "<br />";
document.body.innerHTML += "Is iPad: " + detectDevice("iPad") + "<br />";
document.body.innerHTML += "Is Android: " + detectDevice("Android") + "<br />";
document.body.innerHTML += "Is Linux: " + detectDevice("Linux") + "<br />";
document.body.innerHTML += "Is Windows: " + detectDevice("Windows") + "<br />";
console.log(device.userAgent, device.platform);