[SIGFOX] How many bytes can I transmit in one message to my device? You can send up to 8 bytes per message to the device (downlink). Last Update: August 8, 2017 December 5, 2016 1403 SIGFOX Q&A Downlink , Sigfox , Transmit Related Knowledge Base Posts -[SIGFOX] How can Radiocrafts help us designing a SIGFOX unit?[SIGFOX] What radio modules are available?[SIGFOX] What does public ID and Key means?