01 The Rule
The mobile version of your site is the primary version for indexing and ranking. Desktop and mobile must serve identical content, structured data, and meta tags. Responsive design is the recommended approach.
Mobile-First Indexing
Last updated: 2025-10-01
02 Rationale
Google crawls and indexes the mobile version of all sites. Any content, markup, or structured data missing from the mobile version is invisible to Google's indexer. Separate mobile sites (m.domain) with reduced content will underperform.
03 Implementation
- Use responsive design — single URL, same HTML, CSS adapts layout
- Ensure all content is visible on mobile (no hidden-by-default sections)
- Include identical structured data on mobile and desktop
- Verify meta robots, canonical, and hreflang tags match across versions
- Test with Google's Mobile-Friendly Test and lighthouse
04 Common Violations & Consequences
Violation
Hiding content behind 'show more' buttons on mobile
Consequence
Google may devalue or ignore hidden content
Violation
Missing structured data on mobile version
Consequence
Rich results eligibility lost
Violation
Different canonical/hreflang on mobile vs desktop
Consequence
Conflicting signals — indexation unpredictable
05 The Fix
Consolidate to responsive design. Remove any content differences between mobile and desktop. Verify with Google Search Console's mobile usability report.