title: Why is the number of mobile-friendly pages on Google Search Console Mobile Usability report less than the number of pages indexed?
body: <p>The Mobile Usability report for one of the websites I maintain is currently showing <strong>215 Valid (mobile-friendly pages)</strong>. At the same time, the Coverage report shows that a total of <strong>399 pages are Valid (have been indexed)</strong>.</p>
  
  <p>I downloaded a list of all the URLs that have been indexed and a list of all URLs that are currently considered mobile-friendly pages. Then I compared the two lists and started checking several of the URLs that are indexed but not shown as mobile-friendly using the URL Inspection tool.</p>
  
  <p>The URL Inspection results for all of the URLs that I have checked show the page as mobile-friendly. An example is shown below:</p>
  
  <p><a href="https://i.stack.imgur.com/BTBQu.png" rel="noreferrer"><img src="https://i.stack.imgur.com/BTBQu.png" alt="Example URL Inspection results"></a></p>
  
  <p>The Mobile Usability report shows <strong>5 URLs with Errors</strong>, so I have information about 220 of the total number of indexed URLS.</p>
  
  <p>I would like to understand what does it mean that there are some URLs that are currently indexed, but are not considered mobile-friendly nor have important mobile usability issues.</p>
  
  <p>Additional info:</p>
  
  <ul>
  <li><p>Two months ago (around November 15), the number of mobile-friendly pages had increased to 248 with no pages showing Errors. That number started to decrease until it reached the current value, but a corresponding number of errors wasn't reported.</p>
  
  <p>It is like some pages were simply removed from the Mobile Usability report, but for no explicit reason.</p>
  
  <p>The number of indexed pages increased by 1 during that same period of time.</p></li>
  <li><p>There was a <a href="https://support.google.com/webmasters/answer/6211453#indexed" rel="noreferrer">Google Search Update on November 25</a> indicating that some reports will show data primarily from mobile-first indexing. Unfortunately is still not clear to me why indexed pages > ( mobile-friendly pages + pages with mobile issues).</p>
  
  <p>Is it incorrect to expect errors to show for all indexed URLs that are not considered mobile-friendly?</p></li>
  </ul>
  
  <p>Thank you for taking the time to review this question.</p>