Limit download speed using PHP

slow-download.php

<?php

// source https://stackoverflow.com/a/12245044/3254912

set_time_limit(0);

$file = array();
$file['name'] = 'image.JPG';
$file['size'] = filesize($file['name']);

header('Content-Type: image/jpeg');
header('Content-Description: file transfer');
header('Content-Disposition: attachment; filename="' . $file['name'] . '"');
header('Content-Length: '. $file['size']);

$open = fopen($file['name'], 'rb');
while( !feof($open) ){
    echo fread($open, 256);
    usleep(750);
}
fclose($open);