Skip to main content

Build a Full-Stack Image Upload App with Node.js, Express, React, and Vite (Beginner Tutorial)

 If you’re new to full-stack web development and want a hands-on project to practice React frontend integration with a + Express backend, this tutorial is for you. In this guide, we’ll walk through a simple but powerful app that lets users upload images, store them on the server, and display them back in the browser.

This project is based on my GitHub repo: . It’s designed to be beginner-friendly, SEO-optimized, and a great starting point for anyone learning JavaScript full-stack development.

🛠️ Technologies Used

Here’s the tech stack powering this project:

  • – JavaScript runtime for the backend.

  • – Lightweight web framework for building REST APIs.

  • Multer – Middleware for handling file uploads.

  • CORS – Enables cross-origin requests between frontend and backend.

  • – Frontend library for building user interfaces.

  • Vite – Fast development server and build tool for React.

  • Fetch API – For making HTTP requests from the frontend.

🎯 Intent of Building This Project

The goal of this project is to:

  • Teach beginners how to connect a React frontend with a backend.

  • Demonstrate how to handle file uploads using Multer.

  • Provide a starter template for building full-stack apps with REST APIs.

  • Show how to integrate frontend-backend communication without running into CORS issues.

⚙️ Backend Setup (Node.js + Express)

The backend provides REST API endpoints for uploading and retrieving images.

Install dependencies


npm install express multer cors


import express from "express";
import cors from "cors";
import multer from "multer";

const app = express();
const PORT = 3000;

// Enable CORS
app.use(cors());

// Configure Multer for file storage
const storage = multer.diskStorage({
  destination: (req, file, cb) => cb(null, "uploads"),
  filename: (req, file, cb) => cb(null, Date.now() + "-" + file.originalname),
});
const upload = multer({ storage });

// Simple test endpoint
app.get("/api/hello", (req, res) => {
  res.json({ message: "Hello World!" });
});

// Upload endpoint
app.post("/api/upload", upload.single("file"), (req, res) => {
  res.json({ file: req.file });
});

// List uploaded images
import fs from "fs";
app.get("/api/images", (req, res) => {
  fs.readdir("uploads", (err, files) => {
    if (err) return res.status(500).json({ error: err });
    res.json({ images: files });
  });
});

app.listen(PORT, () => console.log(`Backend running on http://localhost:${PORT}`));

🎨 Frontend Setup (React + Vite)

The frontend provides a simple UI for selecting and uploading files.

Install dependencies


npm create vite@latest frontend
cd frontend
npm install


import React, { useState } from "react";

function App() {
  const [file, setFile] = useState(null);
  const [message, setMessage] = useState("");

  const handleUpload = async () => {
    const formData = new FormData();
    formData.append("file", file);

    const response = await fetch("http://localhost:3000/api/upload", {
      method: "POST",
      body: formData,
    });

    const data = await response.json();
    setMessage(`File uploaded: ${data.file.filename}`);
  };

  return (
    <div>
      <h1>React + Node.js File Upload</h1>
      <input type="file" onChange={(e) => setFile(e.target.files[0])} />
      <button onClick={handleUpload}>Upload</button>
      <p>{message}</p>
    </div>
  );
}

export default App;

🔗 Connecting Frontend and Backend

To avoid CORS issues, configure Vite’s proxy in vite.config.js:


export default {
  server: {
    proxy: {
      "/api": "http://localhost:3000",
    },
  },
};

This ensures that API calls from React (/api/...) are forwarded to the backend running on port 3000.

📸 Displaying Uploaded Images

You can extend the frontend to fetch and display uploaded images:


const [images, setImages] = useState([]);

const fetchImages = async () => {
  const response = await fetch("/api/images");
  const data = await response.json();
  setImages(data.images);
};

useEffect(() => {
  fetchImages();
}, []);

return (
  <div>
    <h2>Uploaded Images</h2>
    {images.map((img, index) => (
      <img key={index} src={`http://localhost:3000/uploads/${img}`} alt={img} />
    ))}
  </div>
);

🧑‍💻 Why This Project Matters

  • Beginner-friendly: Perfect for those learning React + integration.

  • Practical use case: File uploads are common in real-world apps (profile pictures, documents, etc.).

  • Scalable foundation: You can extend this into a full photo gallery, cloud storage integration, or even an AI-powered image app.

✅ Conclusion

This project is a hands-on introduction to full-stack development using modern tools like React and Vite on the frontend, and + Express on the backend. By following this tutorial, you’ll learn how to handle file uploads, build REST APIs, and connect frontend and backend seamlessly.

👉 Check out the full repo here:

Comments

Popular posts from this blog

Upload to AWS S3 from Java API

In this post, you will see code samples for how to upload a file to AWS S3 bucket from a Java Spring Boot app. The code you will see here is from one of my open-source repositories on Github, called document-sharing. Problem Let’s say you are building a document sharing app where you allow your users to upload the file to a public cloud solution. Now, let’s say you are building the API for your app with Spring Boot and you are using AWS S3 as your public cloud solution. How would you do that? This blog post contains the code that can help you achieve that. Read more below,  Upload to AWS S3 bucket from Java Spring Boot app - My Day To-Do (mydaytodo.com)

Addressing app review rejections for auto-renewing subscription in-app purchase (iOS)

The ability to know what the weather is like while planning your day is a feature of  My Day To-Do  Pro and as of the last update it’s also a part of the  Lite version . Unlike the Pro version it’s an auto-renewing subscription based  in-app purchase (IAP)  in the Lite version. What means is that when a user purchases it, the user only pays for the subscription duration after which the user will be automatically charged for the next period. Adding an  auto-renewing  subscription based IAP proved to be somewhat challenging in terms of the app store review i.e. the app update was rejected by the App Review team thrice because of missing information about the IAP. Therefore in this post I will share my experiences and knowledge of adding auto-renewing IAP in hopes to save someone else the time that I had to spend on this problem. In-App purchase This year I started adding IAPs to My Day To-Do Lite which lead to learning about different types of IAP...

Serving HTML content in an iOS app that works in iOS 7 and later (using Swift)

As I have mentioned in an earlier post , I really enjoying coding in Swift. Now what am I doing with it? Well I am trying to build an HTML5 app that must work on devices with iOS 7. So in iOS8 apple has introduced a whole bunch of features that facilitate easy communication between web content and lets just call it back-end Swift code, but those features are not in iOS 7. So why do I want to build something that would work in an older OS? well I do not expect existing iOS users to upgrade to iOS 8 straight away and i also know a couple of people who would be very reluctant to upgrade their iPhones to iOS 8. Now in case you do not, you can have a read of the "Working with WebViews" section of this post , to know how to serve HTML content with WebViews. So when I started building my app, I wanted to know: How do I invoke some Swift code from my HTML content? Well the solution to this may feel a little bit "hacky" but it is a solution to achieve this.  The followi...