Route::middleware('minifier')->view('welcome.blade.php');

app/Http/Kernel.php
app/Http/middlewares/Minifier.php

    function minifyHTML($htmlString)
    {
        $replace = [
            '<!--(.*?)-->' => '', //remove comments
            "/<\?php/" => '<?php ',
            "/\n([\S])/" => '$1',
            "/\r/" => '', // remove carriage return
            "/\n/" => '', // remove new lines
            "/\t/" => '', // remove tab
            "/\s+/" => ' ', // remove spaces
        ];
        return preg_replace(array_keys($this->replace), array_values($this->replace), $htmlString);
    }

<?php

namespace App\Http\Middleware;

use Closure;

class Minifier
{
    public function handle($request, Closure $next)
    {

    }
}