debug-optimize-lcp
What is LCP and why it matters
Largest Contentful Paint (LCP) measures how quickly a page's main content becomes visible. It's the time from navigation start until the largest image or text block renders in the viewport.
- Good: 2.5 seconds or less
- Needs improvement: 2.5–4.0 seconds
- Poor: greater than 4.0 seconds
LCP is a Core Web Vital that directly affects user experience and search ranking. On 73% of mobile pages, the LCP element is an image.
LCP Subparts Breakdown
Every page's LCP breaks down into four sequential subparts with no gaps or overlaps. Understanding which subpart is the bottleneck is the key to effective optimization.
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