What are Laravel Middlewares and how do they work?

Question

What are Laravel Middlewares and how do they work?

Answer

Middleware acts as a series of layers around the HTTP request/response cycle. Each middleware can inspect the request, modify it, pass it to the next layer, or terminate it early (e.g. redirect unauthenticated users).

Creating Middleware

php artisan make:middleware EnsureUserIsActive

// app/Http/Middleware/EnsureUserIsActive.php
class EnsureUserIsActive
{
    public function handle(Request $request, Closure $next): Response
    {
        if (! $request->user()?->is_active) {
            return redirect('/suspended');
        }

        return $next($request); // pass to the next middleware / controller
    }
}

Registering Middleware

// bootstrap/app.php
->withMiddleware(function (Middleware $middleware) {
    $middleware->alias([
        'active' => EnsureUserIsActive::class,
    ]);
})

Applying to Routes

Route::get('/dashboard', [DashboardController::class, 'index'])
    ->middleware(['auth', 'active']);

Types of Middleware

• Global — runs on every request
• Route — applied to specific routes or groups
• Terminable — runs after the response is sent