Is there a way to detect the device when going on a website to change the content

Question

I want to do the following, when somebody visits my website on the phone it should say "please visit from desktop" and when it gets visited by desktop its normal. How can I make the website detect the device and so on?

Answer 1

try to add this code in html header

<script>
  if (/Android|iPhone/i.test(navigator.userAgent)) {
    document.querySelector("body").textContent = "Please, visit from desktop!";
  }
</script>