The Ultimate Race between NestJs vs Express JS

When it comes to backend development in Node.js, two major frameworks stand out: ExpressJS and NestJS. Both are popular, but which one should you use? Let’s break it down in a simple and easy way.

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1. What are ExpressJS and NestJS?

ExpressJS:

• A minimal and flexible Node.js web framework.
• Helps in building APIs and web applications quickly.
• Very lightweight with fewer built-in features.

NestJS:

• A full-fledged Node.js framework built on ExpressJS (by default).
• Uses TypeScript and follows an Angular-like structure.
• Provides dependency injection, decorators, and modular architecture.

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2. Core Differences Between NestJS and ExpressJS

Feature	ExpressJS	NestJS
Type	Micro-framework	Full-fledged framework
Architecture	Unstructured	Modular & scalable
Built-in Features	Minimal	Dependency Injection, Middleware, Guards, Pipes, etc.
Performance	Faster for small apps	Better for large-scale apps
Learning Curve	Easier for beginners	Steeper, but scalable
TypeScript Support	Optional	Built-in
Best For	Small apps, quick APIs	Large apps, enterprise applications
Community Support	Large	Growing rapidly

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3. How Easy is it to Start?

ExpressJS: Getting Started

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

app.get('/', (req, res) => {
    res.send('Hello, ExpressJS!');
});

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

✅ Very simple, minimal setup.

NestJS: Getting Started

import { Controller, Get } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { Module } from '@nestjs/common';

@Controller()
class AppController {
    @Get()
    getHello(): string {
        return 'Hello, NestJS!';
    }
}

@Module({
    controllers: [AppController],
})
class AppModule {}

async function bootstrap() {
    const app = await NestFactory.create(AppModule);
    await app.listen(3000);
    console.log('Server is running on port 3000');
}
bootstrap();

✅ More structured, requires understanding modules and decorators.

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4. Performance & Speed Comparison

Scenario	ExpressJS	NestJS
Simple API Request (Hello World)	Slightly faster	Slightly slower (because of extra layers)
Large-Scale Application	Hard to maintain	Better structured & scalable
Real-World Performance	Fast for small apps	Efficient for enterprise apps
Memory Usage	Lower	Slightly higher due to additional features

💡 ExpressJS is faster for small apps, but NestJS is better for maintainability in large apps.

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5. Real-Life Use Cases

When to Choose ExpressJS?

• If you need a quick and lightweight API.
• When working on small to medium-scale applications.
• If you prefer a JavaScript-first approach.

When to Choose NestJS?

• When building enterprise-grade applications.
• If you need better scalability and maintainability.
• If you prefer a TypeScript-first approach.
• When working on microservices or monolithic architectures.

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6. Middleware & Extensibility

ExpressJS Middleware

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

app.use((req, res, next) => {
    console.log('Middleware executed');
    next();
});

app.get('/', (req, res) => {
    res.send('Hello, Middleware!');
});

app.listen(3000);

✅ Simple middleware integration.

NestJS Middleware

import { Injectable, NestMiddleware } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express';

@Injectable()
class LoggerMiddleware implements NestMiddleware {
    use(req: Request, res: Response, next: NextFunction) {
        console.log('Middleware executed');
        next();
    }
}

✅ More structured middleware integration.

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7. Error Handling

ExpressJS Error Handling

app.use((err, req, res, next) => {
    console.error(err.stack);
    res.status(500).send('Something broke!');
});

NestJS Error Handling

import { ExceptionFilter, Catch, ArgumentsHost, HttpException } from '@nestjs/common';

@Catch(HttpException)
class HttpErrorFilter implements ExceptionFilter {
    catch(exception: HttpException, host: ArgumentsHost) {
        console.log('Error:', exception.message);
    }
}

✅ NestJS provides a more structured way to handle errors.

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8. Testing

Feature	ExpressJS	NestJS
Unit Testing	Manual setup	Built-in support with Jest
Integration Testing	Need extra libraries	Built-in tools available
E2E Testing	Uses third-party tools	Comes with testing utilities

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9. Final Verdict

Category	Winner
Ease of Learning	ExpressJS
Performance (Small Apps)	ExpressJS
Scalability (Large Apps)	NestJS
Best for Enterprise Apps	NestJS
Best for Quick APIs	ExpressJS
Built-in Features	NestJS

🔹 Use ExpressJS for small, fast applications. 🔹 Use NestJS for large, structured, scalable apps.

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10. Conclusion

If you are working on a small API or a quick project, go with ExpressJS. It’s simple and fast. But if you are planning for enterprise-level applications, microservices, or better architecture, NestJS is the best choice.

🚀 NestJS is like an advanced version of ExpressJS with better structure, scalability, and TypeScript support.

Hope this comparison helps! Happy coding! 🎯