Mobile-First Indexing

Definition

Mobile-first indexing means Google predominantly uses the mobile version of a page's content for indexing and ranking. Since July 2019, all new websites are indexed mobile-first by default, and since March 2021, Google has completed the switch for all sites. This means if your mobile site has less content, fewer links, or different structured data than your desktop version, Google only sees the mobile version. Key requirements: ensure content parity between mobile and desktop, use responsive design (recommended by Google), make all structured data present on mobile pages, ensure images have proper alt text on mobile, and verify your site works well on mobile devices. Test with Google's Mobile-Friendly Test tool.