AJAX file uploads, how do they work?! Well, they kinda don't. Browsers don't allow file uploads via XMLHttpRequest (aka XHR) for security reasons. If we try to submit a form remotely via XHR, it will work, except with the file field stripped out of the request parameters. This sort of partial, silent failure can lead to unicorn black-eyes. (I punch unicorns in the face when I'm frustrated.) This i