Framework Integration

While Web Quality Skills are framework-agnostic, each framework provides specialized tools and patterns for implementing performance, accessibility, and SEO optimizations. This guide shows you how to apply skill recommendations in your framework of choice.

Core Web Vitals by Framework

Optimizing LCP (Largest Contentful Paint)

The LCP element is typically a hero image or large text block. Each framework provides optimized image components.

import Image from 'next/image';

export default function Hero() {
  return (
    <Image 
      src="/hero.jpg"
      priority          // Preloads with high priority
      fill              // Fills container
      sizes="100vw"     // Responsive sizing
      alt="Hero image"
    />
  );
}

Key features:

Automatic WebP/AVIF generation
Built-in lazy loading (disabled with priority)
Automatic responsive images via sizes
Image optimization at build time

<template>
  <NuxtImg
    src="/hero.jpg"
    preload
    loading="eager"
    sizes="100vw"
    alt="Hero image"
  />
</template>

Key features:

Uses @nuxt/image module
Automatic format optimization
CDN integration support
Responsive image generation

---
import { Image } from 'astro:assets';
import hero from '../assets/hero.jpg';
---

<Image 
  src={hero} 
  loading="eager" 
  decoding="sync"
  alt="Hero image"
  widths={[400, 800, 1200]}
  sizes="100vw"
/>

Key features:

Built-in image optimization
Multiple format generation
Type-safe image imports
Automatic width generation

export default function Hero() {
  return (
    <>
      {/* Preload in head */}
      <link 
        rel="preload" 
        href="/hero.jpg" 
        as="image" 
        fetchpriority="high" 
      />

      <picture>
        <source srcset="/hero.avif" type="image/avif" />
        <source srcset="/hero.webp" type="image/webp" />
        <img 
          src="/hero.jpg" 
          width="1200" 
          height="600"
          fetchpriority="high"
          alt="Hero image"
        />
      </picture>
    </>
  );
}

Manual optimization required:

Create multiple formats (AVIF, WebP, JPEG)
Add preload hints manually
Use <picture> for format fallbacks

<template>
  <picture>
    <source :srcset="heroAvif" type="image/avif" />
    <source :srcset="heroWebp" type="image/webp" />
    <img 
      :src="heroJpg" 
      :style="{ aspectRatio: '16/9' }"
      width="1200" 
      height="600"
      alt="Hero image"
    />
  </picture>
</template>

<script setup>
const heroAvif = '/hero.avif';
const heroWebp = '/hero.webp';
const heroJpg = '/hero.jpg';
</script>

Best practices:

Use computed properties for dynamic image paths
Bind aspect-ratio to prevent CLS
Optimize images with build tools

<script>
  const images = {
    avif: '/hero.avif',
    webp: '/hero.webp',
    jpg: '/hero.jpg'
  };
</script>

<picture>
  <source srcset={images.avif} type="image/avif" />
  <source srcset={images.webp} type="image/webp" />
  <img 
    src={images.jpg}
    width="1200" 
    height="600"
    alt="Hero image"
    style="aspect-ratio: 16/9;"
  />
</picture>

Svelte advantages:

Reactive image switching
Minimal runtime overhead
Easy style binding

Optimizing INP (Interaction to Next Paint)

INP measures responsiveness. Heavy event handlers and re-renders are common culprits.

React
Vue
Svelte
Next.js

import { useState, useTransition, useMemo } from 'react';

function ExpensiveList({ items }) {
  const [filter, setFilter] = useState('');
  const [isPending, startTransition] = useTransition();

  // Defer non-urgent updates
  const handleFilterChange = (e) => {
    startTransition(() => {
      setFilter(e.target.value);
    });
  };

  // Memoize expensive computations
  const filteredItems = useMemo(() => {
    return items.filter(item => 
      item.name.toLowerCase().includes(filter.toLowerCase())
    );
  }, [items, filter]);

  return (
    <>
      <input 
        onChange={handleFilterChange} 
        placeholder="Filter..."
      />
      {isPending && <div>Updating...</div>}
      <List items={filteredItems} />
    </>
  );
}

// Prevent unnecessary re-renders
const List = React.memo(({ items }) => {
  return items.map(item => <Item key={item.id} item={item} />);
});

Key techniques:

useTransition for non-urgent updates
useMemo for expensive calculations
React.memo to prevent re-renders
useCallback for stable function references

<template>
  <div>
    <input v-model="filter" placeholder="Filter..." />
    <TransitionGroup>
      <ListItem 
        v-for="item in filteredItems" 
        :key="item.id" 
        :item="item" 
      />
    </TransitionGroup>
  </div>
</template>

<script setup>
import { ref, computed } from 'vue';

const filter = ref('');
const items = ref([/* ... */]);

// Computed properties are cached
const filteredItems = computed(() => {
  return items.value.filter(item => 
    item.name.toLowerCase().includes(filter.value.toLowerCase())
  );
});
</script>

<script>
// Use v-once for static content
// Use v-memo for conditional caching
</script>

Key techniques:

Computed properties for caching
v-once for static content
v-memo for conditional memoization
Async components for code splitting

<script>
  let filter = '';
  let items = [/* ... */];

  // Reactive statement (auto-memoized)
  $: filteredItems = items.filter(item => 
    item.name.toLowerCase().includes(filter.toLowerCase())
  );

  // Debounce for expensive operations
  import { debounce } from './utils';
  const debouncedFilter = debounce((value) => {
    filter = value;
  }, 300);
</script>

<input 
  on:input={(e) => debouncedFilter(e.target.value)} 
  placeholder="Filter..."
/>

{#each filteredItems as item (item.id)}
  <ListItem {item} />
{/each}

Key techniques:

Reactive statements ($:) are auto-memoized
Minimal runtime overhead
Built-in keyed each blocks
Easy event handler optimization

'use client'; // Mark as client component

import { useState, useTransition } from 'react';
import dynamic from 'next/dynamic';

// Lazy load heavy components
const HeavyChart = dynamic(() => import('./HeavyChart'), {
  ssr: false,
  loading: () => <div>Loading chart...</div>
});

export default function Dashboard() {
  const [showChart, setShowChart] = useState(false);
  const [isPending, startTransition] = useTransition();

  const handleToggle = () => {
    startTransition(() => {
      setShowChart(!showChart);
    });
  };

  return (
    <>
      <button onClick={handleToggle}>Toggle Chart</button>
      {isPending && <div>Loading...</div>}
      {showChart && <HeavyChart />}
    </>
  );
}

Key techniques:

dynamic() for code splitting
Server Components reduce client JS
useTransition for smooth interactions
Streaming with Suspense

Optimizing CLS (Cumulative Layout Shift)

Prevent unexpected layout shifts by reserving space for dynamic content.

Next.js
All Frameworks

import Image from 'next/image';

// Image component automatically prevents CLS
<Image 
  src="/photo.jpg" 
  width={800} 
  height={600} 
  alt="Photo" 
/>

// For dynamic content, reserve space
<div style={{ minHeight: '200px' }}>
  {loading ? <Skeleton /> : <Content />}
</div>

// Use CSS aspect-ratio for responsive layouts
<div style={{ aspectRatio: '16/9', width: '100%' }}>
  <iframe src="..." />
</div>

// Set dimensions on all images
<img src="photo.jpg" width="800" height="600" alt="Photo" />

// Or use aspect-ratio
<img 
  src="photo.jpg" 
  style={{ aspectRatio: '4/3', width: '100%' }} 
  alt="Photo" 
/>

// Reserve space for ads/embeds
<div style={{ minHeight: '250px' }}>
  <AdComponent />
</div>

// Use font-display to prevent font shifts
<style>
  @font-face {
    font-family: 'Custom';
    src: url('/font.woff2') format('woff2');
    font-display: optional; // or swap with size-adjust
  }
</style>

Code Splitting & Lazy Loading

import { lazy, Suspense } from 'react';

// Component-level code splitting
const HeavyComponent = lazy(() => import('./HeavyComponent'));

function App() {
  return (
    <Suspense fallback={<LoadingSpinner />}>
      <HeavyComponent />
    </Suspense>
  );
}

// Route-based splitting
const Dashboard = lazy(() => import('./pages/Dashboard'));
const Profile = lazy(() => import('./pages/Profile'));

import dynamic from 'next/dynamic';

// Component splitting with SSR disabled
const DynamicComponent = dynamic(
  () => import('./HeavyComponent'),
  { 
    ssr: false,
    loading: () => <LoadingSpinner />
  }
);

// Automatic route-based splitting
// pages/dashboard.js automatically code-split

<script setup>
import { defineAsyncComponent } from 'vue';

// Async component
const HeavyComponent = defineAsyncComponent(() =>
  import('./HeavyComponent.vue')
);
</script>

<template>
  <Suspense>
    <template #default>
      <HeavyComponent />
    </template>
    <template #fallback>
      <LoadingSpinner />
    </template>
  </Suspense>
</template>

<template>
  <!-- Automatic code splitting -->
  <LazyHeavyComponent v-if="showComponent" />
</template>

<script setup>
// Components prefixed with 'Lazy' are auto-lazy-loaded
const showComponent = ref(false);
</script>

<script>
  let Component;
  let loading = false;

  async function loadComponent() {
    loading = true;
    const module = await import('./HeavyComponent.svelte');
    Component = module.default;
    loading = false;
  }
</script>

<button on:click={loadComponent}>Load Component</button>

{#if loading}
  <LoadingSpinner />
{:else if Component}
  <svelte:component this={Component} />
{/if}

---
// Partial hydration - load JS only when needed
import HeavyComponent from './HeavyComponent.jsx';
---

<!-- Only loads JS when visible -->
<HeavyComponent client:visible />

<!-- Only loads JS when idle -->
<InteractiveWidget client:idle />

<!-- Only loads JS on media query match -->
<MobileMenu client:media="(max-width: 768px)" />

<!-- Never loads JS (static only) -->
<StaticContent />

Error Handling

React
Vue
Svelte

class ErrorBoundary extends React.Component {
  state = { hasError: false };
  
  static getDerivedStateFromError(error) {
    return { hasError: true };
  }
  
  componentDidCatch(error, info) {
    // Log to error tracking service
    console.error('Error:', error, info);
  }
  
  render() {
    if (this.state.hasError) {
      return <ErrorFallback />;
    }
    return this.props.children;
  }
}

// Usage
<ErrorBoundary>
  <App />
</ErrorBoundary>

<script setup>
import { onErrorCaptured } from 'vue';

onErrorCaptured((err, instance, info) => {
  console.error('Error captured:', err, info);
  // Return false to prevent propagation
  return false;
});
</script>

<!-- Global error handler in main.js -->
<script>
app.config.errorHandler = (err, instance, info) => {
  console.error('Global error:', err);
};
</script>

<script>
  import { onMount } from 'svelte';

  let error = null;

  onMount(() => {
    window.addEventListener('error', (e) => {
      error = e.error;
    });
  });
</script>

{#if error}
  <ErrorDisplay {error} />
{:else}
  <App />
{/if}

SEO & Meta Tags

Next.js
Nuxt
Astro
React/Vue

import Head from 'next/head';

export default function Page() {
  return (
    <>
      <Head>
        <title>Page Title - Site Name</title>
        <meta 
          name="description" 
          content="Compelling page description" 
        />
        <meta property="og:title" content="Page Title" />
        <meta property="og:description" content="..." />
        <link rel="canonical" href="https://example.com/page" />
      </Head>
      <main>{/* Content */}</main>
    </>
  );
}

// Or use Next.js 13+ Metadata API
export const metadata = {
  title: 'Page Title',
  description: 'Page description',
};

<script setup>
useHead({
  title: 'Page Title - Site Name',
  meta: [
    {
      name: 'description',
      content: 'Compelling page description'
    },
    {
      property: 'og:title',
      content: 'Page Title'
    }
  ],
  link: [
    {
      rel: 'canonical',
      href: 'https://example.com/page'
    }
  ]
});
</script>

---
const title = 'Page Title - Site Name';
const description = 'Compelling page description';
---

<html lang="en">
  <head>
    <title>{title}</title>
    <meta name="description" content={description} />
    <meta property="og:title" content={title} />
    <link rel="canonical" href="https://example.com/page" />
  </head>
  <body>
    <slot />
  </body>
</html>

// Use react-helmet or @vueuse/head
import { Helmet } from 'react-helmet';

function Page() {
  return (
    <>
      <Helmet>
        <title>Page Title - Site Name</title>
        <meta name="description" content="..." />
        <link rel="canonical" href="https://example.com/page" />
      </Helmet>
      <main>{/* Content */}</main>
    </>
  );
}

Core Web Vitals

Deep dive into LCP, INP, and CLS optimization

Performance

Comprehensive performance optimization guide

Get Started

Core Concepts

Guides

Core Web Vitals by Framework

Optimizing LCP (Largest Contentful Paint)

Optimizing INP (Interaction to Next Paint)

Optimizing CLS (Cumulative Layout Shift)

Code Splitting & Lazy Loading

Error Handling

SEO & Meta Tags

Core Web Vitals

Performance

Build docs developers (and LLMs) love

Get Started

Core Concepts

Guides

​Core Web Vitals by Framework

​Optimizing LCP (Largest Contentful Paint)

​Optimizing INP (Interaction to Next Paint)

​Optimizing CLS (Cumulative Layout Shift)

​Code Splitting & Lazy Loading

​Error Handling

​SEO & Meta Tags

​Related Resources

Core Web Vitals

Performance

Build docs developers (and LLMs) love

Core Web Vitals by Framework

Optimizing LCP (Largest Contentful Paint)

Optimizing INP (Interaction to Next Paint)

Optimizing CLS (Cumulative Layout Shift)

Code Splitting & Lazy Loading

Error Handling

SEO & Meta Tags

Related Resources