Introduction
Modern web development is evolving rapidly. Teams use different frontend frameworks — Angular, React, Vue, or even plain JavaScript — within the same organization.
But this raises a key challenge:
How can we share UI components across multiple frameworks without rewriting them for each one?
That’s where Web Components come in.
They offer a standardized way to create reusable, encapsulated UI elements that can work in any web framework — or even without one.
In this article, we’ll understand how Web Components work, how to integrate them with Angular, and why they represent the future of cross-framework reusability.
What Are Web Components?
Web Components are a set of W3C standards that allow developers to build custom HTML elements with their own functionality, encapsulated styling, and independent lifecycle — all running natively in the browser.
They’re composed of four main technologies:
| Technology | Purpose |
|---|
| Custom Elements | Define your own HTML tags (like <user-card>). |
| Shadow DOM | Encapsulate HTML, CSS, and JavaScript within a component. |
| HTML Templates | Define reusable HTML snippets that can be cloned. |
| ES Modules | Import/export component logic easily across files. |
Why Web Components?
Traditional frameworks lock you into their ecosystem.
For example, a React component cannot be used directly in Angular or Vue without rewriting.
Web Components solve this by being framework-agnostic and browser-native.
You can write a component once and use it anywhere — even in plain HTML.
Benefits
True reusability across frameworks (Angular, React, Vue).
Encapsulated styling: no CSS conflicts.
Performance: they’re native to browsers, not framework abstractions.
Longevity: based on web standards, not framework versions.
Microfrontend ready: ideal for enterprise projects using multiple frameworks.
Technical Workflow (Flowchart)
Here’s a simple technical workflow showing how Web Components interact with Angular and the browser runtime.
┌─────────────────────────┐
│ Angular App │
└───────┬─────────────────┘
│ Uses custom element tag
▼
┌─────────────────────────┐
│ Web Component (JS) │
│ - Shadow DOM │
│ - Custom Element logic │
│ - Template & styling │
└───────┬─────────────────┘
│ Registered in Browser
▼
┌─────────────────────────┐
│ Browser Runtime │
│ - Parses Custom Element │
│ - Executes lifecycle │
│ - Renders Shadow DOM │
└─────────────────────────┘
Step-by-Step: Creating a Web Component
Let’s create a simple user-card component using Vanilla JavaScript.
Step 1: Create the Component
// user-card.jsclass UserCard extends HTMLElement {
constructor() {
super();
const shadow = this.attachShadow({ mode: 'open' });
shadow.innerHTML = `
<style>
.card {
padding: 10px;
border: 1px solid #ddd;
border-radius: 8px;
box-shadow: 0 2px 4px rgba(0,0,0,0.1);
width: 200px;
text-align: center;
font-family: Arial, sans-serif;
}
h3 { margin: 8px 0; color: #2c3e50; }
</style>
<div class="card">
<h3>${this.getAttribute('name')}</h3>
<p>${this.getAttribute('role')}</p>
</div>
`;
}
}
customElements.define('user-card', UserCard);
Step 2: Use It in Plain HTML
<!DOCTYPE html>
<html lang="en">
<head>
<script type="module" src="./user-card.js"></script>
</head>
<body>
<user-card name="Rajesh Gami" role="Full Stack Developer"></user-card>
</body>
</html>
That’s it!
You’ve created a standalone, reusable HTML element that doesn’t depend on any framework.
Integrating Web Components with Angular
Now, let’s see how to integrate this component into an Angular app.
Step 1: Include the Web Component Script
Add the Web Component JS file in angular.json:
"scripts": ["src/assets/web-components/user-card.js"]
Step 2: Use It in an Angular Template
<!-- app.component.html --><h2>Team Members</h2>
<user-card name="Rajesh Gami" role="Senior Developer"></user-card>
<user-card name="Hemant Patel" role="Backend Engineer"></user-card>
Step 3: Tell Angular to Ignore the Custom Tag
Angular, by default, doesn’t recognize non-Angular elements.
To fix this, add CUSTOM_ELEMENTS_SCHEMA in your module.
import { NgModule, CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
@NgModule({
declarations: [AppComponent],
imports: [BrowserModule],
bootstrap: [AppComponent],
schemas: [CUSTOM_ELEMENTS_SCHEMA]
})
export class AppModule {}
Now Angular will allow <user-card> to render properly.
Passing Data and Handling Events
Web Components can receive attributes or custom events just like normal HTML elements.
Example: Passing Properties Dynamically
@Component({
selector: 'app-root',
template: `
<user-card [attr.name]="userName" [attr.role]="userRole"></user-card>
`
})
export class AppComponent {
userName = 'Gamee Rajeshbhai';
userRole = 'Sr. Full Stack Developer';
}
Example: Custom Event from Web Component
// Inside user-card.jsthis.dispatchEvent(new CustomEvent('cardClicked', { detail: { name: this.getAttribute('name') } }));
<!-- app.component.html --><user-card (cardClicked)="onCardClick($event)"></user-card>
Styling and Shadow DOM
Each Web Component has a Shadow DOM, meaning its styles are encapsulated.
This avoids CSS conflicts between frameworks — for example, Angular Material styles will not override your Web Component’s internal styles.
To style the host element:
:host {
display: block;
margin: 10px;
}
Angular Elements (Alternative Approach)
Angular also supports building Web Components using Angular Elements, which allows you to wrap Angular components into a native Web Component.
Example
import { Injector, NgModule, CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { createCustomElement } from '@angular/elements';
import { ProfileCardComponent } from './profile-card.component';
@NgModule({
declarations: [ProfileCardComponent],
imports: [BrowserModule],
schemas: [CUSTOM_ELEMENTS_SCHEMA],
})
export class AppModule {
constructor(private injector: Injector) {
const el = createCustomElement(ProfileCardComponent, { injector });
customElements.define('profile-card', el);
}
ngDoBootstrap() {}
}
Now <profile-card> can be used outside Angular, just like a Web Component.
Real-World Use Case
Scenario: Enterprise Dashboard Shared Across Teams
Suppose a company uses:
They can build reusable Web Components such as:
<employee-profile>
<status-indicator>
<file-uploader>
Each app can import the same component without reimplementation, ensuring a consistent design and behavior across all frontends.
Performance Considerations
Lazy load large components using dynamic imports:
import('./charts-widget.js');
Avoid large frameworks inside Web Components — keep them light.
Reuse Shadow DOM templates to improve rendering speed.
Cache component assets via Service Workers for faster load.
Best Practices
| Practice | Description |
|---|
| Prefix components | Use unique names like <app-user-card> to avoid conflicts. |
| Keep logic minimal | Web Components should focus on UI; business logic stays outside. |
| Use Slots | To allow flexible content projection. |
| Bundle with Rollup or Vite | For lightweight packaging. |
| Version your components | Tag releases for easier dependency management. |
Limitations to Keep in Mind
SEO challenges: Web Components may need server-side rendering support.
Limited binding: Data binding is manual compared to Angular templates.
Polyfills required for older browsers (IE11).
Complex communication between frameworks if deep nesting occurs.
Despite these, the tradeoff is worth it for long-term flexibility.
Technical Advantages for Enterprise Projects
Cross-team collaboration: Shared UI components across tech stacks.
Reduced maintenance: One codebase for multiple platforms.
Gradual migration: Replace legacy UI piece by piece.
Future-proof: Based on web standards, not framework versions.
Conclusion
Web Components are not just a trend — they are the foundation for the next generation of reusable, framework-independent UIs.
When combined with frameworks like Angular, they give developers the best of both worlds:
In large-scale enterprise environments, this approach dramatically reduces duplication, improves maintainability, and ensures consistent user experiences across applications.
By embracing Web Components today, you’re building applications that can evolve smoothly — no matter which frameworks dominate tomorrow.