Sites that follow the best practices for mobile-first indexing will be migrating over now, and Google will send notifications via Search Console.
Google has announced that it has begun the process of rolling out the mobile-first indexing to more sites. This rollout is only for sites that “follow the best practices for mobile-first indexing,” Google said.
This is the first time Google has confirmed it is moving a large number of sites to this mobile-first indexing process. Google did tell us last October that a limited number of sites had been moved over. But this Google announcement makes it sound like the process of mobile-first indexing on a larger scale has already begun.
Google did say it will notify webmasters/site owners that their sites are migrated to the mobile-first indexing process via messages in the Google Search Console. Here is a screen shot of a notification:
Google also said “site owners will see significantly increased crawl rate from the Smartphone Googlebot. Additionally, Google will show the mobile version of pages in Search results and Google cached pages.”
What is mobile-first indexing?
Google says it is about how Google crawls your site. Google will only have one index, but how Google crawls and creates the index will be based on a mobile-first experience going forward. Google wrote:
To recap, our crawling, indexing, and ranking systems have typically used the desktop version of a page’s content, which may cause issues for mobile searchers when that version is vastly different from the mobile version. Mobile-first indexing means that we’ll use the mobile version of the page for indexing and ranking, to better help our — primarily mobile — users find what they’re looking for.
Google has a detailed developer document on mobile-first indexing.