Today, most people are searching on Google using a mobile device. However, their ranking systems still typically look at the desktop version of a page’s content to evaluate its relevance to the user. This can cause issues when the mobile page has less content than the desktop page because their algorithms are not evaluating the actual page that is seen by a mobile searcher.
To make their results more useful, they've begun experiments to make their index mobile-first. Although their search index will continue to be a single index of websites and apps, their algorithms will eventually 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. Of course, while their index will be built from mobile documents, they're going to continue to build a great search experience for all users, whether they come from mobile or desktop devices.
They understand this is an important shift in their indexing and it’s one they take seriously. They'll continue to carefully experiment over the coming months on a small scale and they’ll ramp up this change when they’re confident that they have a great user experience. Though they’re only beginning this process, here are a few recommendations to help webmasters prepare as they move towards a more mobile-focused index.
- If you have a responsive site or a dynamic serving site where the primary content and markup is equivalent across mobile and desktop, you shouldn’t have to change anything.
- If you have a site configuration where the primary content and markup is different across mobile and desktop, you should consider making some changes to your site.
- Make sure to serve structured markup for both the desktop and mobile version.
Sites can verify the equivalence of their structured markup across desktop and mobile by typing the URLs of both versions into the Structured Data Testing Tool and comparing the output.
When adding structured data to a mobile site, avoid adding large amounts of markup that isn’t relevant to the specific information content of each document.
- Use the robots.txt testing tool to verify that your mobile version is accessible to Googlebot.
- Sites do not have to make changes to their canonical links; they’ll continue to use these links as guides to serve the appropriate results to a user searching on desktop or mobile.
- If you are a site owner who has only verified their desktop site in Search Console, please add and verify your mobile version.
- If you only have a desktop site, they'll continue to index your desktop site just fine, even if they're using a mobile user agent to view your site.
If you are building a mobile version of your site, 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.
If you have any questions,you can contact them via the Webmaster forums or their public events.
Source: Google Webmaster Blog