In keeping with Google's mobile-first strategy, the company's search engine crawlers will increasingly consider the mobile version of a website's content first when indexing and ranking the sites' search results.
Mobile-first indexing is a shift away from Google's current practice of crawling, indexing and ranking websites by looking at the desktop version of the site content first.
The move is designed to ensure that mobile users searching for content online don't run into issues on websites where the desktop version of a page's content is very different from the mobile version, the company said in a blog Dec. 18.
If Google only uses the desktop version to index a website in such situations, its algorithms would not be evaluating the actual pages served to the mobile user, according to the company.
This week's blog is actually a reminder for webmasters and site operators to prepare for the change. Google actually first announced plans for mobile-first indexing in November 2016. Since then the company has been talking about the policy via Google Hangouts and events like Pubcon search and social media marketing conference.
Google has not laid out a formal timeframe for the shift to mobile-first indexing. The company has acknowledged the significance of the shift and has committed to implementing it in a slow and phased manner though it is not clear when it intends to complete the transition.
Eventually, while Google's search index will continue to be a single index for sites and apps, the company's search algorithms will primarily use a site's mobile content to index and rank it. The snippets that users see of a website's content and also the content that Google caches will be from a site's mobile version of its web content.
"Mobile-first indexing means that we'll use the mobile version of the content for indexing and ranking, to better help our–primarily mobile–users find what they're looking for," the company noted in its announcement Monday. Webmasters and web site owners can expect to see significantly increased crawling of their sites by Google's smartphone Googlebot as a result of the shift to mobile-first indexing.
Google's blog Monday offered several tips on what webmasters and operators can do to get their sites ready for the new way of search indexing and ranking.
One way to maintain ranking is to make sure that the mobile version of a web page has the same content as the desktop version, Google said. All text, videos and images in the desktop version of a web page should be available and crawl-able by Google's bots in the mobile version as well.
Structured data should be included in both the desktop and mobile versions of the site and all URLs embedded in the structured data need to be updated to the mobile versions, the company said.
Metadata too should be present on the mobile version of the site just as it is with the desktop version. All titles used in a page and also meta-descriptions need to be equivalent across the mobile and desktop versions of a site.
Google will start evaluating sites for mobile-first indexing using the criteria described in Monday's blog. The company has already started the processes on a small number of sites and is monitoring the results Google claimed.
Sites that do not have a mobile version will continue to be crawled, indexed and ranked as usual though the crawling itself might be done by Google's smartphone bot. "We believe taking this slowly will help webmasters get their sites ready for mobile users, and because of that, we currently don't have a timeline for when it's going to be completed."