Comprehensive Guide to Angular 20 — New Features and Enhancements

Angular 20, officially released in May 2025, brings a host of exciting improvements and is one of the most significant updates in the Angular ecosystem. If you’re wondering what’s new in Angular 20, this version introduces modern reactivity with signals, zoneless change detection, signal-based forms, improved styling, and enhanced server-side rendering (SSR). In this article, we will take a deep dive into what’s new in Angular 20, exploring its new features, why they matter, and how to leverage them effectively in your projects.

1. Signals: The New Reactive Primitives

Signals are the cornerstone of Angular 20’s reactive system. They represent reactive state containers that notify when their value changes, allowing Angular components and other consumers to automatically update based on those changes.

What Are Signals?

A Signal is a special reactive variable that stores a value and can notify any dependent consumers when the value changes. Unlike observables, signals provide synchronous updates and simpler, fine-grained reactivity.

Basic Signal Usage

// Create a signal
const count = signal(0);

// Read the signal value
console.log(count());

// Update the signal value
count.set(count() + 1);
  

Computed Signals

Signals can depend on other signals using computed(), which automatically recalculates whenever the underlying signals change.

const firstName = signal('John');
const lastName = signal('Doe');

const fullName = computed(() => `${firstName()} ${lastName()}`);

console.log(fullName()); // John Doe

firstName.set('Jane');
console.log(fullName()); // Jane Doe
  

Why Signals Matter

• Automatic and efficient UI updates.
• Reduced need for complex subscriptions and manual change detection.
• Improved performance with fine-grained reactive updates.

2. Zoneless Change Detection (Preview)

Angular traditionally relies on Zone.js to detect async operations and trigger change detection automatically. Angular 20 introduces a new zoneless mode that removes the dependency on Zone.js, enabling better performance and more control over change detection.

Benefits of Zoneless Angular

• Reduced bundle size by removing Zone.js dependency.
• More predictable change detection cycle.
• Cleaner stack traces, easier debugging.

How to Enable Zoneless Mode

// main.ts
import { bootstrapApplication } from '@angular/platform-browser';
import { provideZoneChangeDetection } from '@angular/core';

bootstrapApplication(AppComponent, {
  providers: [
    provideZoneChangeDetection({ eventCoalescing: true }) // Enable zoneless mode
  ]
});
  

3. Signal-Based Forms (Preview)

Angular 20 introduces a new reactive forms API built on signals. This replaces the traditional FormGroup and FormControl with simpler reactive primitives.

Creating Signal Forms

import { signalFormGroup, signalFormControl } from '@angular/forms/signals';

const loginForm = signalFormGroup({
  email: signalFormControl(''),
  password: signalFormControl('')
});

loginForm.controls.email.setValue('user@example.com');
  

Advantages of Signal Forms

• Simpler and more concise API.
• Automatic reactive updates with signals.
• Improved performance due to finer change detection.

4. The Resource API: Simplified Async State Management

Angular 20 introduces a resource() API to simplify managing loading, error, and data states when fetching asynchronous data.

Using the Resource API

const userResource = resource(fetchUser, {
  initialValue: null
});

// Access data, loading and error states
userResource.loading; // boolean
userResource.error; // any
userResource.data; // fetched data
  

Benefits

• Automatic loading and error handling states.
• Cleaner and more declarative async code.
• Seamless integration with signals and change detection.

5. Hydration and SSR Improvements

Server-side rendering (SSR) is essential for SEO and fast initial loads. Angular 20 enhances SSR with true hydration support, allowing the client to seamlessly take over server-rendered markup with minimal overhead.

Why Hydration?

Hydration improves performance by reusing existing DOM from the server instead of re-rendering everything on the client.

Angular 20 Hydration Features

• Automatic tracking of server-rendered nodes.
• Minimal JavaScript needed on the client to bootstrap.
• Improved perceived performance and SEO.

6. Styling Improvements

Angular 20 brings enhancements to styling, including better tree shaking of styles and improved support for Tailwind CSS and other utility-first frameworks.

Scoped Styles and Tree Shaking

Unused styles are now removed more effectively, resulting in smaller bundle sizes.

Tailwind CSS Integration

Angular 20 optimizes integration with popular CSS frameworks like Tailwind, improving build speed and reducing output CSS size.

7. Smaller Bundle Sizes and Performance

By combining zoneless mode, better tree shaking, and signals, Angular 20 apps deliver smaller JavaScript bundles and faster runtime performance.

Performance Metrics

• Up to 30% reduction in bundle size.
• Improved initial load times.
• Faster runtime updates with signals.

8. Improved Developer Experience

Angular 20 offers improved debugging tools and error messages, making it easier for developers to diagnose issues and optimize apps.

Better Stack Traces

Zoneless mode removes Zone.js related noise from stack traces, resulting in clearer, more actionable error messages.

Enhanced DevTools Support

The Angular DevTools extension now supports signals and zoneless mode, providing insights into signal dependencies and reactive updates.

9. Backwards Compatibility and Migration

Angular 20 is backward compatible with Angular 15/16/17. Existing applications can upgrade incrementally and adopt new features like signals and zoneless mode at their own pace.

Migration Path

• Use the Angular CLI update command to migrate.
• Incrementally adopt signals in new components.
• Opt-in for zoneless mode when ready.
• Test SSR hydration if applicable.

10. Complete Feature Summary Table

Conclusion

Angular 20 is a groundbreaking release that pushes the framework into a new era of reactivity and performance. Signals enable fine-grained reactive updates with an elegant API, zoneless mode opens doors for faster and cleaner change detection, and SSR hydration enhances the user experience for server-rendered apps. With improvements in forms, styling, and developer tools, Angular 20 provides a modern and efficient platform for building scalable web applications.

Whether you are starting a new project or upgrading an existing one, Angular 20 offers features that will make your development faster, your apps lighter, and your users happier.

Happy coding with Angular 20!