$xmlWriter = new XMLWriter(); $xmlWriter->openMemory(); $xmlWriter->startDocument('1.0', 'UTF-8'); $xmlWriter->startElement('shop'); for ($i=0; $i<=1000000; ++$i) { $productId = uniqid(); $xmlWriter->startElement('product'); $xmlWriter->writeElement('id', $productId); $xmlWriter->writeElement('name', 'Some product name. ID:' . $productId); $xmlWriter->endElement(); // Flush XML in memory to file every 1000 iterations if (0 == $i%1000) { file_put_contents('example.xml', $xmlWriter->flush(true), FILE_APPEND); } } $xmlWriter->endElement(); // Final flush to make sure we haven't missed anything file_put_contents('example.xml', $xmlWriter->flush(true), FILE_APPEND);