On  December 19, Google announced that over half of the pages displayed in search results globally are from Google indexing that content using mobile-first indexing procedure.  This means that there’s a good chance that the pages you visit from a Google search are based on how Google crawled and indexed that content based on the mobile version of that page.

For those who may still not know, mobile-first indexing is simply how Google crawls and indexes the web.  Rather than the desktop version of the page, Google looks at the mobile version of the page.  This means that Google is crawling and indexing your web page based on how it renders on a mobile phone versus a desktop computer.

There are several sources you can go to about about mobile-first indexing on this site. Here are some of the more important stories:

You can also learn more from this Google help document and more articles on this site.

Typically, Google will notify you when your site has moved to mobile-first indexing within Google Search Console.  Keep checking your messages in the Google Search Console to see if you’ve gotten this notification.  Google even labels your site as last crawled by the Googlebot smartphone useragent in the URL inspection tool as another signal that your site has moved over.

According to Google, you should pay attention to your structured data and alt-text for images on mobile pages with this change.

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