At the end of 2018, Google said mobile-first indexing — that is, using a website’s mobile version to index its pages — was being used for over half the web pages in Google search results.
Today, Google announced that mobile-first indexing will now be the default for all new web domains as of July 1, 2019.
That means that when a new website is registered it will be crawled by Google’s smartphone Googlebot, and its mobile-friendly content will be used to index its pages, as well as to understand the site’s structured data and to show snippets from the site in Google’s search results, when relevant.
The mobile-first indexing initiative has come a long way since Google first announced its plans back in 2016.
In December 2017, Google began to roll out mobile-first indexing to a small handful of sites, but didn’t specify which ones were in this early test group.
Last March, mobile-indexing began to roll out on a broader scale.