Why is my mobile site failing the Core Web Vitals Assessment?

Topic summary

Multiple users are experiencing failed Core Web Vitals assessments specifically on mobile devices, while desktop versions pass. The primary issue centers on Largest Contentful Paint (LCP) metrics.

Key Problems Identified:

  • Mobile sites failing Core Web Vitals despite desktop passing
  • LCP appears as the main failing metric
  • One user notes confusion as their LCP shows green but assessment still fails
  • Another user questions whether Google Ads might be contributing to mobile performance issues

Suggested Solutions:

  • Focus on resolving LCP issues to achieve passing status
  • Use ranksite.in tool for detailed analysis and improvement recommendations
  • Review expanded LCP component details for specific optimization targets

Current Status: The discussion remains open with users seeking specific guidance on fixing mobile LCP issues. Several screenshots were shared showing the failing assessments, though technical details about root causes haven’t been fully explored.

Summarized with AI on November 10. AI used: claude-sonnet-4-5-20250929.

Hi there, can you please share the expanded view of your LCP component, also you can login on https://www.ranksite.in to generate a free report detailing about fixes and improving core web vitals.

Thanks