<?php

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

require 'vendor/autoload.php';

use Knp\Snappy\Pdf;

$snappy = new Pdf('C:\"Program Files"\wkhtmltopdf\bin\wkhtmltopdf.exe');

$url1 = "https://www.google.com/?q=wkhtmltopdf";
$url2 = "https://www.google.com/?q=snappy";
$url3 = "https://www.google.com/?q=php-html-to-pdf";

header('Content-Type: application/pdf');

// https://github.com/KnpLabs/snappy/blob/master/src/Knp/Snappy/Pdf.php#L78
$snappy->setOption('margin-top', '0px');
$snappy->setOption('margin-bottom', '0px');
$snappy->setOption('margin-left', '0px');
$snappy->setOption('margin-right', '0px');

$snappy->setOption('dpi', '300'); // 300 DPI A4 Size = 297mm*210mm / 3508px*2480px

echo $snappy->getOutput([$url1,$url2,$url3]);