web-perf

The web-perf skill performs comprehensive web performance audits using Chrome DevTools MCP to help identify and diagnose issues affecting page load speed and user experience. It focuses on measuring Core Web Vitals such as Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS), along with supplementary metrics like First Contentful Paint (FCP), Total Blocking Time (TBT), and Speed Index. By analyzing real performance traces and network activity, it provides evidence-based insights into bottlenecks and inefficiencies in modern web applications.

This skill leverages Chrome DevTools performance tracing and analysis tools to examine render-blocking resources, network dependency chains, layout shifts, caching behavior, and accessibility gaps. It follows a structured workflow that includes capturing a performance trace, analyzing Core Web Vitals, inspecting network requests, and optionally reviewing accessibility and codebase characteristics. It emphasizes verification before making recommendations, quantifies performance impact, and avoids suggesting optimizations with negligible benefit. Additionally, it prioritizes retrieving up-to-date guidance from authoritative sources such as web.dev and Chrome documentation.

The web-perf skill is suited for developers, performance engineers, and technical auditors who need to profile, debug, or optimize website performance and Lighthouse scores. It is particularly useful for diagnosing slow page loads, improving user experience metrics, and validating performance improvements. It can be applied to both first-party applications and third-party websites, although codebase analysis may be limited for external sites. This makes it a practical tool for ongoing performance monitoring and targeted optimization efforts.