An Introduction to Web Components for Reusable Code

Web Development Series

In modern web development, writing clean, scalable, and maintainable code is just as important as creating beautiful, functional user interfaces. That’s where Web Components come in. They provide a standardised way to build reusable, encapsulated HTML elements, enabling developers to create component-based architectures natively—without relying on frameworks like React or Vue.

In today’s post, we’ll explore what Web Components are, why they matter, and how you can start using them to simplify your front-end workflow.

💡 What Are Web Components?

Web Components are a set of web platform APIs that allow you to create custom, reusable HTML elements with their own functionality, styling, and encapsulated structure.

They’re built on native browser technologies and can work across different frameworks—or without any frameworks at all.

Web Components consist of three core technologies:

1. Custom Elements

Allow you to define your own HTML tags (e.g., <user-card>).

2. Shadow DOM

Encapsulates styles and markup, preventing them from affecting or being affected by the rest of the page.

3. HTML Templates

Let you define reusable chunks of HTML, which can be cloned and attached to the DOM.

🔧 Why Use Web Components?

Here’s why developers are embracing Web Components:

• ✅ Reusability: Create elements once and reuse them across pages or projects
• ✅ Encapsulation: Styles and logic are self-contained—no CSS bleed or global conflicts
• ✅ Framework Agnostic: Works with any framework or standalone
• ✅ Improved Maintainability: Break complex interfaces into smaller, manageable pieces
• ✅ Native Support: No need for heavy libraries or polyfills (modern browsers support them)

🚀 Example: Creating a Simple Web Component

Let’s build a custom <hello-world> element using Web Components.

htmlCopyEdit<!-- index.html -->
<hello-world></hello-world>

<script>
  class HelloWorld extends HTMLElement {
    constructor() {
      super();
      const shadow = this.attachShadow({ mode: 'open' });
      shadow.innerHTML = `
        <style>
          p {
            font-family: sans-serif;
            colour: #333;
          }
        </style>
        <p>Hello, Web Components!</p>
      `;
    }
  }

  customElements.define('hello-world', HelloWorld);
</script>

What’s Happening Here:

• class HelloWorld extends HTMLElement to create a new custom tag
• this.attachShadow() attaches a shadow DOM to encapsulate the component
• The inner HTML includes styles and markup visible only inside the component

🧱 Real-World Use Cases

Web Components are perfect for building reusable UI blocks such as:

🌐 Framework Compatibility

One of the most appealing things about Web Components is their framework-agnostic nature. You can use them in:

• Plain HTML/CSS/JavaScript projects
• React (with dangerouslySetInnerHTML or wrappers)
• Angular (with CUSTOM_ELEMENTS_SCHEMA)
• Vue (as wrapper components)

🔎 Note: While most frameworks support Web Components, the level of integration and syntax may vary slightly.

🧠 Things to Consider

Before you dive in, here are a few points to keep in mind:

• Browser Support: Modern browsers fully support Web Components, but older ones (like IE11) require polyfills
• Server-Side Rendering (SSR): SSR can be tricky—consider this if SEO is a concern
• Learning Curve: Understanding lifecycle callbacks and Shadow DOM takes a bit of practice
• Tooling: Debugging and styling may feel different compared to traditional development

🛠 Tools & Libraries That Support Web Components

🎯 Final Thoughts

Web Components offer a powerful, future-proof way to build reusable, encapsulated UI elements using just the tools the browser gives you. They simplify web development by encouraging modular architecture and clean code separation—while keeping your app fast and lightweight.

Whether you’re building a design system or trying to avoid framework lock-in, Web Components are a valuable addition to your toolkit.