Google has begun testing the use of the mobile version of a website's content to rank pages from that site in its Search results, instead of using the desktop version of the content as the company has been doing all these years.
The company's search index will continue to be a single index of websites and applications. But Google's search algorithms increasingly will use primarily the mobile version for indexing sites, ranking pages and for showing snippets from a webpage or website in its results.
In a blog post, Google product manager Doantam Phan described the move as an important shift for the company and for website owners in general. The goal is to improve search results as users increasingly move to a mobile-first world, Phan said.
"Today, most people are searching on Google using a mobile device," he said. "However, our ranking systems still typically look at the desktop version of a page's content to evaluate its relevance to the user."
Google will implement the shift in increments over the next several months. The company will test the use of mobile content for primary indexing on a small scale initially and ramp it up only after ensuring that the change delivers a better experience for Google Search users, Phan said.
Websites that have the same content and markup for both their desktop and mobile content should feel little impact from the change and will continue to be indexed in the same way.
But website owners should consider making some changes to their sites in when the content and markup are different for desktop and mobile, Phan noted.
For example, such sites should make sure they serve structured markup for both their mobile and desktop versions. But they should be careful to use only relevant markup when adding structured data to a mobile site, Phan said.
He pointed website owners to a Google Structured Data Testing Tool they can use to verify if the structured markup they have is consistent across both their mobile and desktop environments.
Website owners who have only verified their desktop sites on Google's Search Console should consider adding the mobile version, as well. They also need to ensure that the mobile site is accessible to Google's web-crawling bots by using tools such as the robots.txt testing tool.
Google's shift will not affect sites that maintain only a desktop version. In such situations, Google will continue to index the site the same way it always has, even though it will use a mobile user agent to view the site.
Phan offered some advice for people and organizations building mobile versions of their websites. "Keep in mind that a functional desktop-oriented site can be better than a broken or incomplete mobile version of the site. It's better for you to build up your mobile site and launch it when ready."
Google's planned change to its site indexing method is consistent with the company's ongoing efforts to get website owners to making their sites more mobile-friendly.
In the past year, for instance, the company has been encouraging site owners to implement a framework called Accelerated Mobile Pages to ensure their pages load faster on mobile pages compared to standard HTML pages. Recently, the company announced that sites that are AMP-enabled will start gaining more prominence in search results compared with non-AMP sites.