Code Splitting and Dynamic Imports
Split your bundle automatically by route and use dynamic import() for on-demand chunks.
Code Splitting and Dynamic Imports is a free Sveltejs Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Sveltejs Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Automatic Splitting
SvelteKit splits bundles per route automatically. Visitors download only the JS for the routes they visit.
Dynamic import
For more granular splitting, use dynamic import() to load modules on demand.
const Heavy = (await import("./Heavy.svelte")).default;Conditional Loading
Only load a heavy library when a specific user action requires it.
async function openEditor() {
const { default: Editor } = await import("./Editor.svelte");
// ...
}Chunk Naming
Vite names chunks intelligently. You can hint with webpackChunkName-style comments if needed.
Preloading
Use data-sveltekit-preload-code to preload route code on hover.
Bundle Size
Smaller initial bundles mean faster page loads and better Core Web Vitals.
Tree-Shaking
SvelteKit (via Vite/Rollup) tree-shakes unused exports automatically.
Lazy Components
Wrap dynamic imports in components that render once loaded.
Pitfalls
Dynamic imports add async boundaries. Handle loading states gracefully.
Bundle Analysis
Use bundle visualizers to identify what to split next.
When Not to Split
For tiny modules, splitting costs more than it saves. Profile to find the right granularity.
Quick Check
How does SvelteKit split bundles by default?
Recap
Code splitting in SvelteKit is automatic per route. Use dynamic import() for finer-grained lazy loading.
Frequently asked questions
Is the “Code Splitting and Dynamic Imports” lesson free?
Yes — the full text of “Code Splitting and Dynamic Imports” is free to read here on the web, and the Sveltejs Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Sveltejs Academy course, upgrade to CoddyKit PRO.
What will I learn in “Code Splitting and Dynamic Imports”?
Split your bundle automatically by route and use dynamic import() for on-demand chunks. You practise Sveltejs Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Sveltejs Academy?
No prior experience is required. Sveltejs Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Code Splitting and Dynamic Imports” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Sveltejs Academy lesson?
Yes. Every Sveltejs Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Code Splitting and Dynamic Imports
- Optimizing Images with @sveltejs/enhanced-img
- Lazy Loading Components
- Profiling SvelteKit Apps