The mobile-first custom element takes "Mobile First" to a whole new level. If viewed on a desktop or tablet, it will embed its content within a mock image of a mobile device. This will allow your users to experience your site as you originally intended. Show me a demo!

The device can be rotated through mouse gestures, to view your site in landscape on the contained mock device.

Why not?

You can check out this code, and then include this element like this:

<script src="mobile-first.js"></script>
<script type="module">
  // or using ES6 modules...
  import './mobile-first.js';
</script>
<mobile-first>
  <h5>Your Page!</h5>
</mobile-first>

Alternatively, you might contain a mobile-only site:

<style type="text/css">
  /** Include this CSS for iframes so they fit the mock device. */
  mobile-first > iframe {
    display: block;
    width: 100%;
    height: 100%;
    border: 0;
  }
</style>
<mobile-first>
  <iframe src="mobile-site.html"></iframe>
</mobile-first>

There are a few attributes that can be modified.

• device controls the mock device used: currently, this supports "nexus5" and "iphone5". By default, mobile-first chooses a random device from its available devices.

• width may be set to explicitly control the width at which the mobile-first element shows a mock device. Below this width, this element will act as a boring div that just contains its content—ideal for your users who are already on a mobile device!

Install mobile-first-element on NPM (or mobile-first with Bower), and include the source.

Tested on Chrome 58+ and Safari 10.1 (without animations), may work on other browsers that support Custom Elements and Shadow DOM.