AJAX File Upload with XMLHttpRequest

To avoid the post_max_size limitation problem... but also out of memory problems on both sides :

On the client side

• use PUT instead of POST :

  xhr.open("put", "upload.php", true);

• add custom headers to specify original FileName and FileSize :

  xhr.setRequestHeader("X-File-Name", file.name);
xhr.setRequestHeader("X-File-Size", file.size);

• use the File object directly in your XHR send method :

  xhr.send(file);

  Please note that the File object can be obtained directly via the “files” property of your input[type=file] DOM object

On the server side

• read the custom headers via $_SERVER :

  $filename = $_SERVER['HTTP_X_FILE_NAME'];
$filesize = $_SERVER['HTTP_X_FILE_SIZE'];

• read file data using php://input :

  $in = fopen('php://input','r');

You'll then be able to send very big files (1GB or more) without any limitation!!!

This code works for FireFox 4+, Chrome 6+, IE10+

Change the post_max_size directive in the ini file

The Ajax call will not limit the size. It is probably the max file size in the php ini file.