The mobile-first index has already begun to roll out slowly to individual sites that are ready for it, as Google has previously confirmed. What does it mean to be “ready,” exactly?
Google’s Gary Illyes explains how to ensure a site is ready for mobile-first indexing. Sites that utilize responsive web design and dynamic serving do not have to make any changes. Beyond that, here is Google’s official advice.
- Make sure your site displays the same key content on mobile as it does on desktop. Text, images, and videos should be easy to crawl on mobile.
- Structured data should be on the mobile and desktop versions of a site. If there are separate mobile and desktop URLs, then the structured data should be updated to the mobile version on mobile pages.
- Metadata, such as titles and descriptions, should be present on both versions of a site.
- Sites using separate mobile URLs can keep their link rel=canonical and link rel=alternate attributes the same.
- Hreflang links on separate mobile URLs should be checked. When using link rel=hreflang elements for internationalization, link between mobile and desktop URLs separately. Your mobile URLs’ hreflang should point to the other language/region versions on other mobile URLs, and similarly link desktop with other desktop URLs using hreflang link elements there.
- Make sure the server hosting a site has the capacity to handle an increased crawl rate from Smartphone Googlebot.
Google will be evaluating sites individually on whether or not the above criteria is met. When the requirements are met, then a site can be transitioned to the mobile-first index.
The search giant is making a deliberate effort not to rush out mobile-first indexing. Google believes that taking it slow will allow more webmasters to prepare and ultimately provide a better experience for mobile search visitors.
With that said, there is no timeline in place for when mobile-first indexing will be fully rolled out. Google previously stated it was aiming for the transition to be completed in early 2018, but now it sounds like it could take longer if needed.