title: Does Firefox Responsive Design Mode have Viewport Zooming disabled by default?
body: <p>If this two pages:</p>
  
  <ul>
  <li><a href="https://internetingishard.com/html-and-css/responsive-design/example/default-viewport-zoom/responsive.html" rel="nofollow noreferrer">https://internetingishard.com/html-and-css/responsive-design/example/default-viewport-zoom/responsive.html</a></li>
  <li><a href="https://internetingishard.com/html-and-css/responsive-design/example/disabled-viewport-zoom/responsive.html" rel="nofollow noreferrer">https://internetingishard.com/html-and-css/responsive-design/example/disabled-viewport-zoom/responsive.html</a></li>
  </ul>
  
  <p>are opened in the Chrome Dev Tools with Device Mode turned on, they look differently. The difference in them is this tag in the head:</p>
  
  <pre><code>&lt;meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0"&gt;
  </code></pre>
  
  <p>However, if I open these pages in Firefox (or in a freshly installed Firefox Developer Edition without any additional plugins) with Responsive Design Mode turned out, they appear the same. Why is this?</p>