The short answer:

Google will crawl and index the mobile version of your site as its primary source for content and ranking signals for your site.

Google used to do this on the desktop version of your website, but they are now saying they "primarily use the mobile version of a site’s content to rank pages from that site, to understand structured data, and to show snippets from those pages in our results."

In December of last year Google shared their tips to help owners of websites get ready for the mobile-first index. It’s prudent to consider Google’s tips and start taking them into consideration because Google will eventually move to a mobile-first index and disregard the desktop version altogether.

Outside of Google’s mobile-first index tips that they've published here are some other key points to consider:

  • It is still only live for a handful of sites
  • This is being actively monitored by Google’s search team
  • It will still be rolled out very slowly and there’s no timeline
  • Check your log files for when the smartphone Googlebot visits

Here are the official tips from Google on the mobile-first index:

Getting your site ready for mobile-first indexing

Mobile-first indexing means that we'll use the mobile version of the content for indexing and ranking, to better help our – primarily mobile – users find what they're looking for.

Main photo by William Iven on Unsplash