Building web applications directly with Node.js HTTP modules can become repetitive and difficult as applications grow.

Express.js simplifies backend development by providing:

• Cleaner routing

• Easier request handling

• Simplified server setup

• Better code organization

This is why Express.js became one of the most popular Node.js frameworks.

In this article, you will learn how to create routes and handle requests using Express.

What is Express.js?

Express.js is a lightweight web framework built on top of Node.js.

It helps developers build:

• APIs

• Web applications

• Backend servers

without writing large amounts of low-level code.

Why Express Simplifies Node.js Development

Without Express, creating routes and handling requests requires more manual work.

Express provides:

• Simple routing methods

• Middleware support

• Easy request and response handling

• Cleaner project structure

This makes development faster and more maintainable.

Raw Node.js HTTP Server Example

Using Node.js HTTP Module

const http = require("http");

const server = http.createServer((req, res) => {
  if (req.url === "/") {
    res.write("Home Page");
    res.end();
  }
});

server.listen(3000);

Even simple routing requires manual conditions.

Express Server Example

Using Express.js

const express = require("express");
const app = express();

app.get("/", (req, res) => {
  res.send("Home Page");
});

app.listen(3000);

The code becomes much cleaner and easier to read.

Installing Express

Initialize project:

npm init -y

Install Express:

npm install express

Creating Your First Express Server

const express = require("express");

const app = express();

app.listen(3000, () => {
  console.log("Server running on port 3000");
});

What is Routing?

Routing means deciding how the server responds to different URLs and request types.

Example:

Express Routing Structure

Client Request
↓
Express Route Matches URL
↓
Route Handler Executes
↓
Response Sent

Handling GET Requests

GET requests are used to retrieve data.

Example

app.get("/users", (req, res) => {
  res.send("User List");
});

Request

GET /users

Response

User List

Handling POST Requests

POST requests are used to send or create data.

Example

app.post("/users", (req, res) => {
  res.send("User Created");
});

Request

POST /users

Response

User Created

Understanding req and res

Every route handler receives:

req

Represents the incoming request.

Contains:

• URL data

• Headers

• Query strings

• Request body

res

Represents the server response.

Used to:

• Send text

• Send JSON

• Set status codes

• End requests

Sending Responses

Sending Text

res.send("Hello World");

Sending JSON

res.json({
  name: "Aman"
});

Sending Status Codes

res.status(404).send("Not Found");

Example: Simple API

const express = require("express");
const app = express();

app.get("/", (req, res) => {
  res.send("Welcome to API");
});

app.get("/users", (req, res) => {
  res.json([
    { id: 1, name: "Aman" },
    { id: 2, name: "Riya" }
  ]);
});

app.post("/users", (req, res) => {
  res.send("New user created");
});

app.listen(3000, () => {
  console.log("Server started");
});

Request → Route → Response Flow

Browser / Client
↓
Request Sent
↓
Express Matches Route
↓
Route Handler Executes
↓
Response Returned

Why Express Became Popular

Developers adopted Express because it:

• Reduces boilerplate code

• Simplifies routing

• Makes APIs easier to build

• Supports middleware architecture

• Integrates well with Node.js ecosystem

Common Beginner Mistakes

Forgetting app.listen()

Without:

app.listen()

server will not start.

Using Wrong HTTP Method

GET and POST routes are different.

app.get()
app.post()

must match request type.

Sending Multiple Responses

Each request should receive only one response.

Key Takeaways

• Express.js simplifies Node.js backend development

• Routing controls server behavior for URLs

• GET requests fetch data

• POST requests send data

• req stores request information

• res sends responses back to client

Conclusion

Express.js makes backend development in Node.js significantly simpler by reducing repetitive code and providing powerful routing features.

Understanding routes and request handling is the foundation for building APIs and scalable backend systems.

Final Tip

Before learning advanced Express concepts like middleware or authentication, first become comfortable with:

• Routes

• Request handling

• Responses

• HTTP methods

These fundamentals form the backbone of every Express application.