Vanilla JavaScript detecting the operating system

I’m sure you’ve ever seen this in action. A website states, “Hey, you’re on macOS, download this specific Mac version.” Or download the Windows EXE here.

It mainly comes down to downloads, but there can be some cool advantages of knowing a user’s browser and system.

In today’s article, we will be using the navigator API to get the appVersion.

The result will look like this:

HTML Document permalink

For our demo, we will be created a simple card that we can render some information.

<div class="card" id="os_card"></div>

CSS Styling permalink

Now let’s make the card look more appealing by centering it and using some colors.

body {
  display: flex;
  min-height: 100vh;
  align-items: center;
  justify-content: center;
  font-family: Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: #f3c4fb;
}
.card {
  background: #e2afff;
  color: #fff;
  box-shadow: 0 10px 20px 0 rgba(0, 77, 115, 0.07);
  border-radius: 10px;
  padding: 30px 40px;
  font-size: 2rem;
}

JavaScript detect Operating System permalink

Now we can go ahead and find the user’s OS!

As mentioned, we make use of the navigator API.

Let’s first declare our starting variables.

const card = document.getElementById('os_card');
let os = 'Unknown';

We also define an empty OS variable if we can’t find the right one.

Now we are going to check if the OS string returns something familiar.

if (navigator.appVersion.indexOf('Win') != -1) os = 'Windows';
if (navigator.appVersion.indexOf('Mac') != -1) os = 'MacOS';
if (navigator.appVersion.indexOf('X11') != -1) os = 'UNIX';
if (navigator.appVersion.indexOf('Linux') != -1) os = 'Linux';

An entire string would look something like this (MacOs)

// 5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.183 Safari/537.36

Now we are going to add our string to our card:

card.innerHTML = 'Your OS: ' + os;

That’s it. See the result in this Codepen.

See the Pen Vanilla JavaScript detecting the operating system by Chris Bongers (@rebelchris) on CodePen.

Browser Support permalink

The Navigator API has excellent support these days!

Thank you for reading, and let’s connect! permalink

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