What problem does it solve? Slow Largest Contentful Paint hurts user experience and search rankings, but finding the real bottleneck among TTFB, resource load delay, load duration, and render delay is difficult without a structured debugging process. ## Core Features & Use Cases - LCP Subpart Breakdown: Records a performance trace with reload and analyzes LCPBreakdown, DocumentLatency, RenderBlocking, and LCPDiscovery insights to pinpoint the bottleneck subpart. - Element and Network Inspection: Identifies the exact LCP element via PerformanceObserver snippets and checks the network waterfall for late-starting or slow-loading resources. - Prioritized Optimization Guidance: Provides targeted fixes per subpart, such as fetchpriority hints, preload links, critical CSS inlining, modern image formats, and CDN caching, plus Fast 3G and CPU throttling emulation for verification. - Use Case: A developer notices a landing page's hero image takes 5 seconds to appear. The skill records a trace, reveals a large resource load delay caused by a lazy-loaded image, and recommends removing loading="lazy" and adding fetchpriority="high". ## Quick Start Ask the agent to debug why my page's Largest Contentful Paint is slow and suggest optimizations using Chrome DevTools.
