// local file that should be send to the client $local_file = 'test-file.zip'; // filename that the user gets as default $download_file = 'your-download-name.zip'; // set the download rate limit (=> 20,5 kb/s) $download_rate = 20.5; if(file_exists($local_file) && is_file($local_file)) {  // send headers  header('Cache-control: private');  header('Content-Type: application/octet-stream');  header('Content-Length: '.filesize($local_file));  header('Content-Disposition: filename='.$download_file);  // flush content  flush();  // open file stream  $file = fopen($local_file, "r");  while (!feof($file)) {  // send the current file part to the browser  print fread($file, round($download_rate * 1024));  // flush the content to the browser  flush();  // sleep one second  sleep(1);  }  // close file stream  fclose($file); } else {  die('Error: The file '.$local_file.' does not exist!'); }