My Laravel application is returning Cache-Control: no-cache, private HTTP header by default for each site. How can I change this behaviour?

P.S.: It is not a PHP.ini problem, because changing session.cache_limiter to empty/public does not change anything.

Laravel 5.5 <

You can have a global middleware for that. something like:

<?php

namespace App\Http\Middleware;

use Closure;

class CacheControl
{
    public function handle($request, Closure $next)
    {
        $response = $next($request);

        $response->header('Cache-Control', 'no-cache, must-revalidate');
        // Or whatever you want it to be:
        // $response->header('Cache-Control', 'max-age=100');

        return $response;
    }
}

then just register this as a global middleware in the Kernel file:

protected $middleware = [
    ....
    \App\Http\Middleware\CacheControl::class
];