JS Check the size of the uploaded file

var freader = new FileReader (), var input = document.getElementById (fileId); Freader.readasarraybuffer (Input.files[0]); Freader.onloadend = function (event) {var uri = event.target.result;if (uri.bytelength/1024/1024 >= 2) {alert ("more than 2M"); return;};}

Search on the Internet a lot of files on the size of the post has never been able to solve my problem, after reading an article FileReader, think of the file size is the sum of its bytes, so wrote this method. Tested by Firefox, Google is available.

JS Check the size of the uploaded file