A Slow Site Loses Rankings Before It Loses Visitors.

Google\'s field data, collected from real Chrome users on your actual visitors\' devices, is what determines your Core Web Vitals score. Not the score from a single Lighthouse test run on a fast laptop. The distinction matters: a site can pass desktop Lighthouse and still have poor field data scores on mobile, which is where most organic search happens.

Our Mobile and Core Web Vitals service starts with a proper diagnostic that pulls CrUX (Chrome User Experience Report) data for your domain to establish your real-world scores by device type and connection speed. We then compare those scores against the 75th percentile threshold that Google uses to classify pages as passing or failing each metric.

LCP failures (slow content rendering) are typically caused by render-blocking resources, large unoptimized images, no preloading of hero images, or slow server response times. CLS failures (layout shift) are usually caused by elements without reserved dimensions -- images, embeds, and ads loading without size attributes. INP failures (interaction delay) are almost always JavaScript execution blocking the main thread.

For each failure, we provide specific implementation guidance: the exact file or resource causing the problem, the recommended fix, and the expected score improvement if the fix is implemented. We also provide a mobile usability audit that covers tap target sizes, text legibility without zooming, and viewport configuration -- factors that affect both user experience and Google\'s mobile usability assessment.