UTF-8のエンコードとデコード - Qiita

function encode(string, encoding) { encoding = encoding || "UTF-8"; if(typeof Buffer === "function") { return new Buffer(string, encoding); } else { var bytes = []; var cs = encodeURI(string).match(/(?:%[0-9A-F]{2})|./g); for(var i = 0, len = cs.length; i < len; i++) { if(cs[i].length === 3) { bytes.push(parseInt(cs[i].slice(1), 16)); } else { bytes.push(cs[i].charCodeAt(0)); } } return bytes; } }