Optimize Bundle Size
This skill helps users minimize their application's bundle size when using Ignite UI Web Components by importing only the components they need and following best practices for tree-shaking.
Example Usage
- "My bundle size is too large"
- "How do I reduce the size of igniteui-webcomponents?"
- "Import only the components I need"
- "Tree-shake unused components"
- "Optimize imports for production"
Related Skills
- igniteui-wc-integrate-with-framework - Proper integration setup
- igniteui-wc-customize-component-theme - Theming after optimization
When to Use
- User's bundle size is too large
- User wants to optimize for production
- User is importing more components than needed
- User asks about tree-shaking or optimization
- User wants to improve load times
Key Principles
- Import only what you use - Don't use
defineAllComponents() - Use named imports - Enable tree-shaking
- Analyze your bundle - Identify what's being included
- Lazy load when possible - Load components on demand
Import Strategies
❌ Bad: Import Everything
// DON'T DO THIS - imports ALL components (~500KB+)
import { defineAllComponents } from 'igniteui-webcomponents';
defineAllComponents();
Impact: Includes all 60+ components whether you use them or not.
✅ Good: Import Specific Components
// DO THIS - import only what you need
import {
defineComponents,
IgcButtonComponent,
IgcInputComponent,
IgcCardComponent
} from 'igniteui-webcomponents';
defineComponents(IgcButtonComponent, IgcInputComponent, IgcCardComponent);
Impact: Bundle includes only 3 components and their dependencies.
React Applications
If you're using React, consider using the igniteui-react package instead of igniteui-webcomponents. It provides the same components with React-friendly wrappers and typically results in better tree-shaking:
npm install igniteui-react
import { IgrButton, IgrInput, IgrCard } from 'igniteui-react';
// No need to call defineComponents - components register automatically
function MyComponent() {
return (
<div>
<IgrButton variant="contained">Click me</IgrButton>
<IgrInput label="Name" />
<IgrCard>Content</IgrCard>
</div>
);
}
Benefits for bundle size:
- Automatic tree-shaking (only imported components are included)
- No need for component registration overhead
- Better integration with React build tools
For more details, see the igniteui-wc-integrate-with-framework skill.
Analyzing Your Bundle
Using Webpack Bundle Analyzer
Installation:
npm install --save-dev webpack-bundle-analyzer
Configuration (webpack.config.js):
const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');
module.exports = {
plugins: [
new BundleAnalyzerPlugin({
analyzerMode: 'static',
openAnalyzer: false,
reportFilename: 'bundle-report.html'
})
]
};
Run analysis:
npm run build
# Open bundle-report.html to see what's included
Using Vite Bundle Analyzer
Installation:
npm install --save-dev rollup-plugin-visualizer
Configuration (vite.config.ts):
import { defineConfig } from 'vite';
import { visualizer } from 'rollup-plugin-visualizer';
export default defineConfig({
plugins: [
visualizer({
open: true,
gzipSize: true,
brotliSize: true,
})
]
});
Run analysis:
npm run build
# Opens stats.html automatically
Using source-map-explorer
Installation:
npm install --save-dev source-map-explorer
Package.json:
{
"scripts": {
"analyze": "source-map-explorer 'dist/**/*.js'"
}
}
Run:
npm run build
npm run analyze
Audit Your Component Usage
1. Find What Components You're Actually Using
Search your codebase for component usage:
# Search for component tags in templates
grep -r "igc-" src/ --include="*.html" --include="*.tsx" --include="*.vue"
# List unique components
grep -roh "igc-[a-z-]*" src/ | sort | uniq
2. Compare with Your Imports
Check what you're importing vs what you're using:
// Find in your code
import {
defineComponents,
IgcButtonComponent,
IgcInputComponent,
IgcCardComponent,
IgcSelectComponent, // ← Are you using this?
IgcComboComponent, // ← Are you using this?
} from 'igniteui-webcomponents';
3. Remove Unused Imports
Remove components you're not using:
// Before: 5 components imported
import {
defineComponents,
IgcButtonComponent,
IgcInputComponent,
IgcCardComponent,
IgcSelectComponent,
IgcComboComponent,
} from 'igniteui-webcomponents';
defineComponents(
IgcButtonComponent,
IgcInputComponent,
IgcCardComponent,
IgcSelectComponent,
IgcComboComponent
);
// After: Only 3 components needed
import {
defineComponents,
IgcButtonComponent,
IgcInputComponent,
IgcCardComponent,
} from 'igniteui-webcomponents';
defineComponents(IgcButtonComponent, IgcInputComponent, IgcCardComponent);
Lazy Loading Components
Load components only when needed to reduce initial bundle size.
Vanilla JavaScript / TypeScript
// Load immediately (increases initial bundle)
import { defineComponents, IgcDialogComponent } from 'igniteui-webcomponents';
defineComponents(IgcDialogComponent);
// Lazy load (smaller initial bundle)
async function showDialog() {
const { defineComponents, IgcDialogComponent } = await import('igniteui-webcomponents');
defineComponents(IgcDialogComponent);
const dialog = document.createElement('igc-dialog');
// ... use dialog
}
React (using igniteui-react)
import React, { lazy, Suspense, useState } from 'react';
// Lazy load the dialog component
const IgrDialog = lazy(() =>
import('igniteui-react').then(module => ({ default: module.IgrDialog }))
);
function MyComponent() {
const [showDialog, setShowDialog] = useState(false);
return (
<>
<button => setShowDialog(true)}>Open Dialog</button>
{showDialog && (
<Suspense fallback={<div>Loading...</div>}>
<IgrDialog open>
<h2>Dialog Content</h2>
</IgrDialog>
</Suspense>
)}
</>
);
}
React (using web components directly)
import React, { useState } from 'react';
// Lazy load component registration
const lazyLoadDialog = async () => {
const { defineComponents, IgcDialogComponent } = await import('igniteui-webcomponents');
defineComponents(IgcDialogComponent);
};
function MyComponent() {
const [dialogReady, setDialogReady] = useState(false);
const openDialog = async () => {
if (!dialogReady) {
await lazyLoadDialog();
setDialogReady(true);
}
// Show dialog
};
return (
<button Dialog</button>
);
}
Vue 3
<script setup lang="ts">
import { ref } from 'vue';
const dialogReady = ref(false);
async function openDialog() {
if (!dialogReady.value) {
const { defineComponents, IgcDialogComponent } = await import('igniteui-webcomponents');
defineComponents(IgcDialogComponent);
dialogReady.value = true;
}
// Show dialog
}
</script>
<template>
<button @click="openDialog">Open Dialog</button>
<igc-dialog v-if="dialogReady" open>
<h2>Dialog Content</h2>
</igc-dialog>
</template>
Angular
import { Component } from '@angular/core';
@Component({
selector: 'app-my-component',
template: `
<button (click)="openDialog()">Open Dialog</button>
<igc-dialog *ngIf="dialogReady" [open]="true">
<h2>Dialog Content</h2>
</igc-dialog>
`
})
export class MyComponent {
dialogReady = false;
async openDialog() {
if (!this.dialogReady) {
const { defineComponents, IgcDialogComponent } = await import('igniteui-webcomponents');
defineComponents(IgcDialogComponent);
this.dialogReady = true;
}
}
}
Route-Based Code Splitting
Load components only for specific routes.
React Router
import { BrowserRouter, Routes, Route } from 'react-router-dom';
import { lazy, Suspense } from 'react';
// Lazy load route components
const HomePage = lazy(() => import('./pages/Home'));
const DashboardPage = lazy(() => import('./pages/Dashboard'));
function App() {
return (
<BrowserRouter>
<Suspense fallback={<div>Loading...</div>}>
<Routes>
<Route path="/" element={<HomePage />} />
<Route path="/dashboard" element={<DashboardPage />} />
</Routes>
</Suspense>
</BrowserRouter>
);
}
In route component (pages/Dashboard.tsx):
import { IgrCard, IgrButton } from 'igniteui-react';
function Dashboard() {
return (
<div>
<IgrCard>
<h2>Dashboard</h2>
<p>Dashboard content here</p>
</IgrCard>
</div>
);
}
Vue Router
// router/index.ts
import { createRouter, createWebHistory } from 'vue-router';
const routes = [
{
path: '/',
component: () => import('../views/Home.vue') // Lazy load
},
{
path: '/dashboard',
component: () => import('../views/Dashboard.vue') // Lazy load
}
];
export default createRouter({
history: createWebHistory(),
routes
});
In route component (views/Dashboard.vue):
<script setup lang="ts">
import { onMounted } from 'vue';
onMounted(async () => {
// Load components only for this route
const { defineComponents, IgcCardComponent } = await import('igniteui-webcomponents');
defineComponents(IgcCardComponent);
});
</script>
Angular
// app-routing.module.ts
import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
const routes: Routes = [
{
path: 'dashboard',
loadChildren: () => import('./dashboard/dashboard.module').then(m => m.DashboardModule)
}
];
@NgModule({
imports: [RouterModule.forRoot(routes)],
exports: [RouterModule]
})
export class AppRoutingModule {}
Build Configuration Optimizations
Vite Configuration
// vite.config.ts
import { defineConfig } from 'vite';
export default defineConfig({
build: {
// Enable minification
minify: 'terser',
terserOptions: {
compress: {
drop_console: true, // Remove console.logs
drop_debugger: true
}
},
// Optimize chunk splitting
rollupOptions: {
output: {
manualChunks: {
// Separate vendor chunks
'vendor': ['igniteui-webcomponents'],
}
}
},
// Set chunk size warning limit
chunkSizeWarningLimit: 600,
},
// Optimize deps
optimizeDeps: {
include: ['igniteui-webcomponents']
}
});
Webpack Configuration
// webpack.config.js
module.exports = {
optimization: {
splitChunks: {
chunks: 'all',
cacheGroups: {
vendor: {
test: /[\\/]node_modules[\\/]/,
name: 'vendors',
priority: 10,
},
igniteui: {
test: /[\\/]node_modules[\\/]igniteui-webcomponents[\\/]/,
name: 'igniteui',
priority: 20,
}
}
},
minimize: true,
},
// Tree shaking
mode: 'production',
};
Size Comparison
Here's what you can expect in terms of bundle size:
| Import Strategy | Approximate Size (gzipped) | Components Included |
|---|---|---|
defineAllComponents() |
~500KB+ | All 60+ components |
10 components via defineComponents() |
~150-200KB | 10 components + deps |
5 components via defineComponents() |
~100-150KB | 5 components + deps |
3 components via defineComponents() |
~80-120KB | 3 components + deps |
1 component via defineComponents() |
~50-80KB | 1 component + deps |
Note: Sizes vary based on which components you import (some have more dependencies than others).
Best Practices Checklist
- Never use
defineAllComponents()unless you truly need every component - Use
defineComponents()with specific components you need - Audit your imports regularly - remove unused components
- Lazy load rarely-used components (dialogs, modals, etc.)
- Split by routes - load components only for active routes
- Analyze your bundle - use bundle analyzer tools
- Enable tree-shaking - use named imports, not side-effect imports
- Minify in production - ensure build tool minification is enabled
- Use compression - enable gzip/brotli on your server
Common Issues and Solutions
Issue: Bundle still large after following best practices
Investigate:
- Check if you're importing many components at once
- Verify tree-shaking is working (check build output)
- Look for duplicate dependencies
- Check if source maps are included in production
- For React, ensure you're using
igniteui-reactinstead ofigniteui-webcomponents
Solutions:
// Review your imports - are you using all of these?
import {
defineComponents,
IgcButtonComponent,
IgcInputComponent,
IgcSelectComponent,
IgcComboComponent,
IgcDatePickerComponent
} from 'igniteui-webcomponents';
// Consider lazy loading components you don't need immediately
async function loadDialog() {
const { defineComponents, IgcDialogComponent } = await import('igniteui-webcomponents');
defineComponents(IgcDialogComponent);
}
Issue: Components not working after optimizing imports
Cause: Forgot to import a component you're using
Solution:
// Error: <igc-button> not working
// You're using igc-button but didn't import it
import { defineComponents, IgcButtonComponent } from 'igniteui-webcomponents';
defineComponents(IgcButtonComponent); // Add this
Issue: TypeScript errors after changing imports
Solution: Update type imports:
// Import types separately if needed
import type { IgcButtonComponent } from 'igniteui-webcomponents';
Monitoring Bundle Size
Set up bundle size monitoring in CI/CD
Using bundlesize (for any build tool):
npm install --save-dev bundlesize
Package.json:
{
"scripts": {
"test:size": "bundlesize"
},
"bundlesize": [
{
"path": "./dist/**/*.js",
"maxSize": "300 kB"
}
]
}
Run in CI:
npm run build
npm run test:size
GitHub Actions Example
name: Bundle Size Check
on: [pull_request]
jobs:
size:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- uses: actions/setup-node@v3
- run: npm ci
- run: npm run build
- run: npm run test:size
Expected Results
After optimization, you should see:
- Initial load time reduced by 40-60%
- Bundle size reduced by 50-80%
- Better Core Web Vitals scores
- Faster time to interactive
- Lower bandwidth usage for users
Next Steps
- Profile your application with Chrome DevTools Performance tab
- Implement lazy loading for heavy components
- Consider using CDN for static assets
- Enable HTTP/2 for better resource loading
- Check igniteui-wc-integrate-with-framework for proper setup