🎯 TL;DR: Angular 20 revolutionizes with Signals + Zoneless = -10.4% transfer size, no Zone.js polyfills, enhanced performance
🧠 Signals: The New Reactivity
What it is: A modern reactivity system that advantageously 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(), // 🎯 Magic!
// ...
],
}📊 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%) | Better 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 automatically update!
}
}🏆 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 marks a turning point in the framework's evolution. With Signals providing intuitive reactivity and Zoneless architecture delivering measurable performance gains, Angular has finally caught up with modern frontend expectations. The combination of simplified state management, reduced bundle size, and improved developer experience makes this upgrade not just recommended, but essential for staying competitive in today's frontend landscape.
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