BundlePhobia Svelte Comparison
A complete analysis of JavaScript framework bundle sizes using BundlePhobia. Real data showing why Svelte ships 15-22x less code than React.
WHAT IS BUNDLEPHOBIA?
Understanding npm package size impact
BundlePhobia
bundlephobia.comA tool that analyzes npm packages to determine their impact on your JavaScript bundle size.
Why it matters: Every KB of JavaScript impacts load time, parse time, and memory usage. On slow 3G networks, 100 KB takes ~2 seconds to download.
Why Bundle Analysis Matters More Than Ever
The fact that BundlePhobia is investing in Rspack infrastructure shows how critical bundle analysis has become. As JavaScript bundles grow and Core Web Vitals impact SEO, tools that help developers understand their bundle composition are essential.
FRAMEWORK BUNDLE COMPARISON
Verified data from multiple community sources and benchmarks (2026)
Visual: Bundle Size at Scale
Height represents relative bundle size. Svelte compiles away, leaving near-zero runtime overhead.
Data verified across multiple community benchmarks, developer reports, and official documentation. See sources at the bottom of this guide.
REAL-WORLD APP BUNDLES
SvelteKit vs Next.js vs Nuxt.js actual app sizes
SvelteKit ships 20x less JavaScript than Next.js for equivalent applications. This translates to dramatically faster load times, especially on mobile devices.
WHY SVELTE PRODUCES SMALL BUNDLES
The compiler approach explained
Compile-Time Optimization
Svelte analyzes your components at build time and generates highly optimized vanilla JavaScript. No framework code ships to the browser.
<script>
let count = $state(0);
</script>
<button onclick={() => count++}>
{count}
</button>// Compiled output (simplified)
let count = 0;
button.onclick = () => {
count++;
text.data = count;
};No Virtual DOM
React and Vue use a Virtual DOM to track changes. Svelte doesn't need one because it knows at compile time exactly which DOM nodes to update.
Native Tree-Shaking
Svelte's output is plain JavaScript that bundlers can tree-shake perfectly. Unused features don't increase bundle size.
Surgical DOM Updates
The compiler generates code that updates only the specific DOM nodes that changed, with no runtime overhead for change detection.
BUNDLE OPTIMIZATION TIPS
Make your Svelte apps even smaller
Code Splitting
Use dynamic imports to load components only when needed.
const HeavyComponent = await import('./HeavyComponent.svelte');Lazy Loading Routes
SvelteKit automatically code-splits routes. Each page loads only its dependencies.
// Routes are automatically lazy-loaded // /src/routes/dashboard/+page.svelte
Analyze with rollup-plugin-visualizer
Visualize your bundle composition to identify optimization opportunities.
// vite.config.ts
import { visualizer } from 'rollup-plugin-visualizer';
plugins: [visualizer({ open: true })]Prefer Lightweight Libraries
Choose libraries designed for small bundles. Check BundlePhobia before installing.
- date-fns (tree-shakeable) vs moment.js
- clsx vs classnames
- lucide-svelte vs react-icons
Lightweight SvelteKit Stack
npx create-stacksfinder@latest --seed SF1-eyJ2IjoxLCJ0Ijoic3RhcnR1cCIsInMiOiJzdGFydHVwIiwiaHAiOlsicGVyZm9ybWFuY2UiLCJkeCJdLCJlIjoiamF2YXNjcmlwdCIsInNlbCI6eyJmcmFtZXdvcmsiOiJzdmVsdGVraXQiLCJvcm0iOiJkcml6emxlIiwiYXV0aCI6ImJldHRlci1hdXRoIiwiZGF0YWJhc2UiOiJuZW9uIn19 --ref guide-bundlephobia-svelte WHEN BUNDLE SIZE MATTERS
Context determines importance
Bundle Size Matters
In emerging markets, users often have 2G/3G connections. Every KB adds seconds of load time.
140 KB on 3G = 2.8s download timeConversion rates drop 7% for each second of load time. Bundle size directly impacts revenue.
Amazon: 100ms slower = 1% less salesPWAs must work offline and load instantly. Smaller bundles mean faster service worker caching.
Smaller bundles = faster cache updatesGoogle's Core Web Vitals penalize slow-loading pages. Large bundles hurt Time to Interactive.
LCP > 2.5s = lower search rankingsBundle Size Matters Less
Users are on fast corporate networks and use the app daily. Initial load time matters less than DX.
Users accept longer loads for feature-rich toolsDesktop users typically have fast connections and powerful devices. 100 KB vs 10 KB is imperceptible.
Both load in <100ms on fiberControlled network environment with guaranteed bandwidth. Bundle size is rarely a bottleneck.
Local servers eliminate network latencyFREQUENTLY ASKED QUESTIONS
Common questions about Svelte bundle size
Frequently Asked Questions
DATA SOURCES
Verify our data
Bundle Size Is Just One Factor
Get personalized stack recommendations based on your project requirements, team expertise, and performance goals. Our algorithm considers 50+ factors beyond bundle size.