Global middleware in Laravel

Introduction

Global middleware runs on every request to your Laravel app. It helps you add common checks or actions for all users.

You want to check if the user is authenticated on every page.

You need to log every request made to your app.

You want to set a security header for all responses.

You want to handle CORS (Cross-Origin Resource Sharing) for all requests.

You want to trim all input data from forms automatically.

Syntax

Laravel

protected $middleware = [
    \App\Http\Middleware\CheckForMaintenanceMode::class,
    \Illuminate\Foundation\Http\Middleware\ValidatePostSize::class,
    \App\Http\Middleware\TrimStrings::class,
    \Illuminate\Foundation\Http\Middleware\ConvertEmptyStringsToNull::class,
];

This code goes inside the app/Http/Kernel.php file.

Each middleware class listed here runs on every HTTP request.

Examples

This example shows adding two middleware globally: one to trust proxies and one to check maintenance mode.

Laravel

protected $middleware = [
    \App\Http\Middleware\TrustProxies::class,
    \App\Http\Middleware\CheckForMaintenanceMode::class,
];

This example trims all input strings and converts empty strings to null for every request.

Laravel

protected $middleware = [
    \App\Http\Middleware\TrimStrings::class,
    \App\Http\Middleware\ConvertEmptyStringsToNull::class,
];

Sample Program

This middleware adds a custom header to every HTTP response. Adding it to the global middleware list makes it run on all requests.

Laravel

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;

class AddCustomHeader
{
    public function handle(Request $request, Closure $next)
    {
        $response = $next($request);
        $response->headers->set('X-Custom-Header', 'HelloWorld');
        return $response;
    }
}

// Then in app/Http/Kernel.php add:
// protected $middleware = [
//     \App\Http\Middleware\AddCustomHeader::class,
//     // other middleware...
// ];

Important Notes

Global middleware affects every request, so keep them efficient to avoid slowing your app.

You can still use route middleware for specific routes if you want to run middleware only sometimes.

Remember to register your custom middleware class in app/Http/Kernel.php under the $middleware array.

Summary

Global middleware runs on every request to your Laravel app.

It is defined in the $middleware array inside app/Http/Kernel.php.

Use it for tasks like authentication checks, logging, or modifying all responses.