02/2021

Multiple resources suggest using the Navigator userAgent property to detect mobile devices. However you must take into account that maybe it's not 100% reliable and some devices could give you "false" (I haven't found any problem yet though).

You can use either match or test.

There are alos different ways of doing it but I just used what I think is efficient.

You can also make use of simple media query but there are cases you would prefer not to use that method.

#2 using .test might be faster that .match "Use .test if you want a faster boolean check. Use .match to retrieve all matches when using the g global flag." src: https://stackoverflow.com/a/10940138/6713989

💡Currently I think I like solution #2

#1

if( navigator.userAgent.match(/Android/i)
 || navigator.userAgent.match(/webOS/i)
 || navigator.userAgent.match(/iPhone/i)
 || navigator.userAgent.match(/iPad/i)
 || navigator.userAgent.match(/iPod/i)
 || navigator.userAgent.match(/BlackBerry/i)
 || navigator.userAgent.match(/Windows Phone/i)

alert("You're using Mobile Device!!")

#1.5

var isMobile = navigator.userAgent.match(
        /(iPhone|iPod|iPad|Android|webOS|BlackBerry|IEMobile|Opera Mini)/i)

#2

if(/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)){
  // true for mobile device  
}else{
  // false for not mobile device
}

#3