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 more than 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. By year-end, half the pages on the web were indexed by Google’s smartphone Googlebot.

Google explained the change to how sites are indexed is aimed at helping the company’s “primarily mobile” users to better search the web. Since 2015, the majority of Google users start their searches from mobile devices. It only makes sense, then, that the mobile versions of the website — and not the desktop pages — would be used to deliver the search results.

Mobile-first indexing isn’t the only way that Google has begun catering to the larger mobile majority.

Several years ago, it also began to boost the rank of mobile-friendly webpages in search. Last year, it added a signal that uses page speed to help determine a page’s mobile search ranking. Starting in July 2018, slow-loading content became downranked.

While many sites today now show the same content to users across desktop and mobile, those that have not yet achieved this parity have a variety of resources to help them get started. Site owners can check for mobile-first indexing of their website by using the URL Inspection Tool in the search console to see when the site was last crawled and indexed. Google also offers a host of documentation on how to make websites work for mobile-first indexing, and suggests that websites support responsive web design — not separate mobile URLs.

“We’re happy to see how the web has evolved from being focused on desktop, to becoming mobile-friendly, and now to being mostly crawlable and indexable with mobile user-agents,” said Google, in its announcement today.