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Sreekar Reddy
Sreekar Reddy

Posted on • Originally published at sreekarreddy.com

🧩 Web Components Explained Like You're 5

Reusable custom HTML elements

Day 131 of 149

👉 Full deep-dive with code examples


The LEGO Brick Analogy

LEGO bricks are reusable building blocks:

  • Each brick works independently
  • Combine them to build anything
  • Same brick works in any LEGO set

Web Components are LEGO bricks for websites!

Create a component once, use it anywhere.


The Problem They Solve

Before Web Components:

  • Copying HTML, CSS, JS between projects
  • Styles from one component affecting others
  • Different frameworks couldn't share components
  • Hard to encapsulate functionality

What Web Components Give You

Custom Elements:

  • Define your own HTML tags
  • <user-card> instead of <div class="user-card">

Shadow DOM:

  • Component has its own isolated styles
  • No CSS leaking in or out

HTML Templates:

  • Reusable HTML structures
  • Only rendered when needed

A Simple Example

Create a custom element:

<my-greeting name="Alice"></my-greeting>
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Renders as:

Hello, Alice! Welcome to our site.
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Use it anywhere like a regular HTML tag!


Benefits

  • Encapsulation → Styles and logic stay inside
  • Reusability → Same component in any project
  • Framework agnostic → Works with React, Vue, or vanilla JS
  • Native browser support → No library needed

Common Uses

  • Design systems → Company-wide UI components
  • Widgets → Video players, date pickers
  • Micro frontends → Independent components from different teams

In One Sentence

Web Components let you create custom, reusable HTML elements with encapsulated styles and behavior that work in any web project.


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