Google announced this morning its “mobile -first” indexing of the web is now starting to roll out, after a year and a half of testing and experimentation. Back in 2016, Google first detailed its plan to change the way its search index operates, explaining how its algorithms would eventually be shifted to use the mobile version of a website’s content to index its pages, as well as to understand its structured data and to show snippets from the site in the Google search results.
In December 2017, Google said it had begun to transition a small handful of sites to mobile-first indexing, but declined to say which properties had been made the move.
Mobile-first indexing means Google will use the mobile version of a web page “for indexing and ranking, to better help our – primarily mobile – users find what they’re looking for,” the company writes in a blog post.
By “primarily mobile,” Google is referring to the fact that the majority of people who use Google search today now do so from mobile devices, and have done so since 2015.
Google also explains that it will have one index for search results, not a mobile-first index that’s separate from its main index. In other words, it will start to look to the mobile web pages to index the web, not the desktop version.
Mobile-friendliness has long been one of the many factors in determining how a site is ranked, but it’s not the only factor. For example, there are times when a non-mobile friendly page still has the best information and will appear higher, Google says.
However, Google has begun to prioritize mobile sites in several ways. For example, it began to boost the rank of mobile-friendly webpages on mobile search results back in 2015, and more recently said it was adding a signal that uses page speed to help determine a page’s mobile search ranking. Starting in July 2018, slow-loading content will be downranked.