If you work in SEO or paid search, you’ve probably seen mobile traffic skyrocket over the last 18-24 months. Anticipating this trend will only continue, Google is experimenting with the way it indexes websites: by looking at the mobile version first.
Historically, the Google algorithm has viewed the desktop version of a site to determine how relevant the content is to users. With mobile-first indexing, however, the search giant will crawl the mobile version of a website instead, and use this signals to build their index.
Google’s search index will still be a single entity—there won’t be a different set of search results for desktop searches vs. those originating on mobile, for example—but, mobile-first indexing places a far greater significance on the version that more users are now likely to see.
Website owners without mobile sites won’t be completely left out in the cold with this change; as Google notes in their blog post announcing the mobile-first indexing experiment, desktop-only sites will continue to be indexed just fine, using Google’s mobile user agent. As we’ve previously reported, not having a mobile site is problematic for other reasons, however, including not receiving a rankings boost via the mobile-friendly algorithm.
Publishers with responsive websites do not need to adjust anything for this new indexing experiment. For those with a site config different across mobile & desktop, website owners should ensure Structured Data is served correctly across each, and check their robots.txt file to make sure Googlebot is not blocked on mobile.
While Google’s mobile-first indexing is rolling out slowly—so the company can work out all of the bugs—expect this to become the new norm over the next 6-12 months.