Agent skill · software engineering · davila7
performance
Optimize web performance for faster loading and better user experience. Use when asked to "speed up my site", "optimize performance", "reduce load time", "fix slow loading", "improve page speed", or "performance audit".
Why this skill is useful
Provides specific code examples and optimization techniques for web performance that the AI wouldn't reliably generate on its own.
What it needs
About 4k tokens when loaded. Last updated 2026-08-06. 30,138 stars on the source repository.
What this skill does
Performance optimization Deep performance optimization based on Lighthouse performance audits. Focuses on loading speed, runtime efficiency, and resource optimization. How it works 1. Identify performance bottlenecks in code and assets 2. Prioritize by impact on Core Web Vitals 3. Provide specific optimizations with code examples 4. Measure improvement with before/after metrics Performance budget Resource Budget Rationale ---------- -------- ----------- Total page weight < 1.5 MB 3G loads in ~4s JavaScript (compressed) < 300 KB Parsing + execution time CSS (compressed) < 100 KB Render blocking Images (above-fold) < 500 KB LCP impact Fonts < 100 KB FOIT/FOUT prevention Third-party < 200 KB Uncontrolled latency Critical rendering path Server response TTFB < 800ms. Time to First Byte should be fast. Use CDN, caching, and efficient backends. Enable compression. Gzip or Brotli for text assets. Brotli preferred (15-20% smaller). HTTP/2 or HTTP/3. Multiplexing reduces connection overhead. Edge caching. Cache HTML at CDN edge when possible. Resource loading Preconnect to required origins: Preload critical resources: Defer non-critical CSS: JavaScript optimization Defer non-essential scripts: Code splitting patterns: Tree shaking best practices: Image optimization Format selection Format Use case Browser support -------- ---------- ----------------- AVIF Photos, best compression 92%+ WebP Photos, good fallback 97%+ PNG Graphics with transparency Universal SVG Icons, logos, illustrations Universal Responsive images LCP image priority Font optimization Loading strategy Preloading critical fonts Variable fonts Caching strategy Cache-Control headers Service worker caching Runtime performance Avoid layout thrashing Debounce expensive operations Use requestAnimationFrame Virtualize long lists Third-party scripts Load strategies Facade pattern Measurement Key metrics Metric Target Tool -------- -------- ------ LCP < 2.5s Lighthouse, CrUX FCP < 1.8s Lighthouse Speed Index < 3.4s Lig …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills davila7/performance