🎯 TL;DR: Angular 20 with Signals + Zoneless = -10.4% transfer size, no Zone.js polyfills, faster performance
🧠 Signals: The New Reactivity
What it is: A reactivity system that replaces RxJS for local state management.
// Before (complex)
this.userService.getUser().pipe(map(user => user.name)).subscribe(...)
// After (simple)
count = signal(0)
doubleCount = computed(() => this.count() * 2)Ultra-simple template:
<div>{{ count() }}</div> <!-- No more | async needed -->⚡ Zoneless: Maximum Performance
Zone.js completely removed = No polyfills + granular change detection
// Angular 19: polyfills needed (34.52 kB)
// Angular 20: ✅ No polyfills needed!
// Simple configuration
export const appConfig: ApplicationConfig = {
providers: [
provideZonelessChangeDetection(),
// ...
],
}📊 Real Measured Results (Custom Starter Kit)
Bundle Size Comparison
| Version | Raw Size | Transfer Size | Features |
|---|---|---|---|
| Angular 19 | 744.97 kB | 144.87 kB | Standard setup |
| Angular 20 | 725.47 kB | 129.78 kB | Signals + Zoneless + Enhanced features |
Performance Gains
| Metric | Improvement | Impact |
|---|---|---|
| Raw Bundle | -19.5 kB (-2.6%) | Faster initial load |
| Transfer Size | -15.09 kB (-10.4%) | Faster network performance |
| Build Time | 2.720s | Optimized compilation |
| Zone.js | ✅ Removed | No polyfills needed |
📈 Key insight: These metrics are from a custom starter kit comparing Angular 19 vs 20. Even with more features in Angular 20, better performance is achieved thanks to Zoneless architecture!
🎨 Winning Pattern
export class ModernComponent {
// Simple state
data = signal<User[]>([])
// Automatic derived state
activeUsers = computed(() => this.data().filter(u => u.active))
// Reactive updates
updateData(newData: User[]) {
this.data.set(newData) // All computed values update automatically
}
}🏆 Why Adopt Now?
✅ Performance: Granular change detection + faster builds (2.720s)
✅ Simplicity: No more RxJS complexity for local state
✅ Bundle: No Zone.js polyfills (34.52 kB saved)
✅ Network: -10.4% transfer size for better loading
🚦 Express Migration
- New project:
provideZonelessChangeDetection() - Existing project: Progressive migration by component
- Pattern replacement:
BehaviorSubject→signal()
🔗 Resources
📚 Learn more
🛠️ Community
Angular 20 represents a significant evolution in the framework. Signals provide intuitive reactivity and Zoneless architecture delivers measurable performance gains. The combination of simplified state management, reduced bundle size, and better developer experience makes this a worthwhile upgrade.
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