🧩 Middleware in Express.js — Explained Simply
Have you ever wondered how Express handles things like authentication, logging, and error handling?
That’s where middleware comes in.
Middleware is a function that runs between the request and the response.
How it works
Client → Middleware → Route → Response
For example, when a user sends a request:
Request
↓
Auth Middleware 🔐
↓
Check user
↓
Controller
↓
Response
Middleware can:
🔐 Check authentication
📝 Log requests
✅ Validate data
🚦 Control access
* ❌ Handle errors
A simple example:
app.use((req, res, next) => {
console.log(req.method, req.url);
next();
});
next() tells Express:
“I’m done. Move to the next middleware or route.”
I hope you gain something
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