Upload in HTML5 We are using HTML5 APIs. Always. Plupload is based on multi-runtime pollyfills for XMLHttpRequest L2, File and Image APIs. So when there's no HTML5 available in the browser, we emulate it ourselves. mOxie (combined code-name for pollyfills) is completely standalone and available separately. Drag'n'Drop Files from Desktop Files not only can be picked from browse dialog, but also can