var a = document.createElement('a'); a.download = 'test.txt'; a.href = window.URL.createObjectURL(new Blob( ['test'], {type: 'application/octet-stream'} )); a.click();

var fileName = 'test.csv'; var type = fileName.split('.'); if (type[type.length - 1].toLowerCase() == 'csv') { alert('csv'); }