What is Mobile-First Indexing?
Mobile-first indexing means Google primarily uses the mobile version of your site for indexing and ranking. If your mobile site differs from your desktop site, the mobile version takes precedence.
History
- 2016: Mobile-first indexing announced
- 2018: Started rolling out to sites
- 2020: Default for all new sites
- 2023: Completed for all sites
What This Means for Your Site
Google's crawler (Googlebot smartphone) evaluates:
- Mobile page content
- Mobile structured data
- Mobile page speed
- Mobile user experience
Mobile-First Best Practices
- Same content on mobile and desktop - Don't hide content on mobile
- Responsive design - One URL, adapts to screen size
- Mobile-optimized images - Proper sizing and lazy loading
- Readable without zooming - Appropriate font sizes
- Touch-friendly - Adequate tap targets
- Fast mobile loading - Optimize for mobile networks
Common Mobile Issues
- Content missing from mobile version
- Different structured data on mobile
- Blocked resources (CSS, JS, images)
- Slow mobile page speed
- Intrusive interstitials (popups)
Checking Mobile-First Status
Use Google Search Console's URL Inspection tool to see which crawler indexed your page (Googlebot smartphone indicates mobile-first indexing).
Why this matters
Mobile-First Indexing influences how search engines and users interpret your pages. When mobile-first indexing is handled consistently, it reduces ambiguity and improves performance over time.
Common mistakes
- Applying mobile-first indexing inconsistently across templates
- Ignoring how mobile-first indexing interacts with canonical or index rules
- Failing to validate mobile-first indexing after releases
- Over-optimizing mobile-first indexing without checking intent
- Leaving outdated mobile-first indexing rules in production
How to check or improve Mobile-First Indexing (quick checklist)
- Review your current mobile-first indexing implementation on key templates.
- Validate mobile-first indexing using Search Console and a crawl.
- Document standards for mobile-first indexing to keep changes consistent.
- Monitor performance and update mobile-first indexing as intent shifts.
Examples
Example 1: A site standardizes mobile-first indexing and sees more stable indexing. Example 2: A team audits mobile-first indexing and resolves hidden conflicts.
FAQs
What is Mobile-First Indexing?
Mobile-First Indexing is a core concept that affects how pages are evaluated.
Why does Mobile-First Indexing matter?
Because it shapes visibility, relevance, and user expectations.
How do I improve mobile-first indexing?
Use the checklist and verify changes across templates.
How often should I review mobile-first indexing?
After major releases and at least quarterly for critical pages.
Related resources
- Guide: /resources/guides/robots-txt-for-ai-crawlers
- Template: /templates/definitive-guide
- Use case: /use-cases/saas-companies
- Glossary:
- /glossary/canonical-url
- /glossary/indexability