core-web-vitals-tuner（核心网络生命体调节器）

Core Web Vitals Tuner

Improve LCP, INP, and CLS systematically.

LCP Optimization (<2.5s)

Prioritized Fixes:

1. Optimize images (Biggest impact) <!-- Before --> <img src="hero.jpg" /> <!-- After --> <img src="hero.jpg" srcset="hero-400.webp 400w, hero-800.webp 800w, hero-1200.webp 1200w" sizes="(max-width: 600px) 400px, (max-width: 1200px) 800px, 1200px" loading="eager" fetchpriority="high" />
2. Preload LCP resource <link rel="preload" as="image" href="/hero.webp" fetchpriority="high" />
3. Inline critical CSS <style> /* Above-the-fold styles */.hero {display: flex; height: 100vh;} </style>
4. Use CDN

- Serve images from CloudFront/Cloudflare - Enable HTTP/2 or HTTP/3

INP Optimization (<200ms)

Fixes:

1. Debounce expensive interactions import {debounce} from "lodash"; const handleSearch = debounce((query) => {fetchResults(query);}, 300);
2. Use Web Workers for heavy tasks const worker = new Worker("processor.js"); worker.postMessage(largeData); worker.onmessage = (e) => console.log(e.data);
3. Code splitting const HeavyComponent = lazy(() => import("./HeavyComponent"));

CLS Optimization (<0.1)

Fixes:

1. Reserve space for images/ads <img src="banner.jpg" width="1200" height="600" />
2. Use CSS aspect-ratio .video-container {aspect-ratio: 16 / 9;}
3. Avoid injecting content above existing .notification {position: fixed; top: 0;}

Verification

# Lighthouse CI
npm run lighthouse -- --url=https://example.com

# Web Vitals in production
import { getCLS, getFID, getLCP } from 'web-vitals';

getCLS(console.log);
getFID(console.log);
getLCP(console.log);

Output Checklist

• LCP optimized (<2.5s)
• INP optimized (<200ms)
• CLS optimized (<0.1)
• Monitoring in place
• Performance regression tests ENDFILE