Since some parameters and values might need to be utf-8 and percent encoded (spaces, &, =, special chars…), you should rather use QUrl (for Qt 4) or QUrlQuery (for Qt 5) to build the posted string. Example code for Qt 4: QUrl postData; postData.addQueryItem(“param1”, “string”); postData.addQueryItem(“param2”, “string”); … QNetworkRequest request(serviceUrl); request.setHeader(QNetworkRequest::ContentTypeHeader, “application/x-www-form-urlencoded”); networkManager->post(request, postData.encodedQuery()); and … Read more