[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 2011 SIGFOX Q&A Downlink , Sigfox , Transmit Related Knowledge Base Posts -[SIGFOX] What is a SIGFOX zone?[SIGFOX] Can I have a trial subscription to test my application?[SIGFOX] How often can I transmit a SIGFOX message?