Google’s Gary Illyes announced back in October that Google’s search engine would begin moving towards Mobile-First Indexing. Now, Google has begun rolling out its experiment, creating a unique index for mobile-sites and prioritizing them over the desktop versions.

So what does this mean? First, you have to understand the difference between crawling, indexing, and ranking.

Crawling, Indexing, Ranking

Websites don’t just pop up in a search engine, they have to first be found. This involves a three-step process: crawling, indexing, and ranking the page. Here’s a more detailed look at each step:


The phase when Google discovers and analyzes web pages on the internet. This is also where nofollow tags or disavows are read and applied.


Refers to the step where Google creates a copy of the webpage and stores it within their database. In this process, Google also formats the copy so that its search engine is ready to analyze and return pertinent information.


This is where the work of SEO specialists and agencies come in. Once Google indexes a page, it then determines how relevant the content on the page is to the user looking for a particular answer or result. Google ranks pages on a number of factors or “signals”, such as domain authority, the number of high-quality backlinks, localized content, and hundreds more, including mobile-friendliness.

Google and Mobile-First Indexing

So what is Mobile-First Indexing? How will this affect the current search results page?

Currently, Google focuses on indexing desktop websites. Googlebot crawls the desktop sites, then generates rankings based on the signals. A mobile Googlebot then gathers the mobile-friendly signal, without creating a new index.

However, Google still serves up results based on desktop versions of a page, even if the user is on a mobile platform. This can lead to issues when the content crawled on the desktop version is missing or incomplete in the stripped-down mobile version.

With Mobile-First Indexing, Google will prioritize indexing the mobile version of a website, forcing developers to reconcile inconsistent gaps between the two versions. It will also create a greater expectation for developers to create a mobile-friendly version of their site in the first place.

How This Affects Your Website

So now you’re up to speed on Google’s plans, how will they affect your website or how you search, if at all? The answer: it depends on the website.

For responsive sites or a dynamic serving sites (mobile-friendly sites)

If your website’s content is consistent between the desktop and mobile versions, then there’s nothing to worry about. Google will index content from both, and users will see the same content.  

For domains with site configuration (separate mobile and desktop sites)

Some websites have a site configuration where primary content between the website and the mobile version are different. In these cases, Google may end up crawling the content on the mobile site, but miss out some content in the desktop version.

If you have a site configuration, be sure to follow these tips.

  • Serve structured markup for both desktop and mobile sites. You can check the structured markup for both the desktop and mobile sites with Google’s Structured Data Testing Tool.
  • Use the robots.txt tester tool. This will ensure your mobile website is being crawled by Googlebot.
  • Sites don’t need to update their canonical links- Google will continue to use these links to serve the most relevant result to the user.

For desktop sites without a mobile version

Google will continue to crawl your site’s content. Even though they are testing mobile-first indexing, it doesn’t imply mobile-only indexing. However, you should still consider getting a mobile-optimized website as mobile-friendliness is a strong ranking factor for Google.

Small-scale Experiment to Worldwide Rollout

Google only started their mobile-first indexing experiment this month. There’s still a lot for them to learn, which is why these tests are smaller in nature, but will gradually be rolled out as a search engine standard. In the meantime, SEO specialists should prepare for the change by ensuring their website can accurately crawled by Googlebot.

For more news and information on the latest SEO news, guides, and tips, visit Arcalea today.

For a more in-depth read on the specific changes Google is making, read Search Engine Journal’s “What Does Mobile First Index Actually Mean?