What is Google’s Mobile-First Index?

Google has always crawled websites to deliver SERPs (search engine result pages), with the goal of efficiently delivering the most relevant, exceptional results to the majority of its users. But with the increase in users coming from mobile devices, Google has decided to switch things up.

In short, Google will use mobile site content as its primary index, and rank results based on content on mobile sites, even for desktop searches. Google will only call on desktop versions when a mobile site is not available.

Learn more about Google’s move to Mobile-First Indexing in our blog ‘Google Experiments With Mobile-First Indexing’.


Expandable Tab Content Will Be Given Full SEO Weight in Mobile-First Index

Historically, “hidden” content that lived in accordions and tabs, not seen in an initial view in order to improve user experience, was not given full weight and may be ignored by Google’s ranking algorithms.

In a reversal of past policies, on July 2017, Google’s John Mueller stated: “On the mobile version of the page it can be that you have these kind of tabs and folders and things like that, which we will still treat as normal content on the page even. Even if it is hidden on the initial view.”



With Google rolling out its mobile-first index on a per-site basis, sites that are prepared for this transition will have a better chance at being indexed before others. “Those that aren’t ready for the mobile-first switch will have to wait a bit longer to be indexed,” Mueller says.


How Will This Impact You?

Google’s Mobile-First Index will give full weight to click-to-expand content and content hidden behind tabs on mobile sites. This is a huge win for SEO because sites that are ready for Google's mobile-first index will have an advantage on SERP rankings. If your site is not yet mobile-friendly, you should consider making this transition ASAP.

To recap:

  • Google’s Mobile-First Index will rank results based on content as it appears to mobile users, even for desktop searches
  • “Hidden” content will be given full SEO credit
  • Google will roll out its mobile-first index on a per-site basis


Any concerns about your company’s readiness for a Mobile-First World? If so, reach out to our team at HDMZ for advice. Email us at client.services@hdmz.com to schedule an audit.