Cacher is the code snippet organizer for pro developers

// https://developer.mozilla.org/en-US/docs/Using_files_from_web_applications

// http://stackoverflow.com/a/11277737/907388
function createObjectURL ( file ) {
    if ( window.webkitURL ) {
        return window.webkitURL.createObjectURL( file );
    } else if ( window.URL && window.URL.createObjectURL ) {
        return window.URL.createObjectURL( file );
    } else {
        return null;
    }
}

// works cross-browser
var url = createObjectURL( file );