The invention relates cloud based IoT network monitoring and validation to enable optimal network selection and connectivity for IoT sensors. The present invention relates to a system to measure the signal quality directly from the network module of IoT sensors. It comprises of an application programming interface (API) 105, a Network detection dongle 103, communication network 110, server 115, network modules of network operators and IoT sensors 120, to be deployed or installed. The invention also relates to a method for determination of signal strength from network module of IoT sensors, wherein the API 105 is configured to run network detection software to determine and validate an optimal location for IoT sensor/device installation or deployment based on the highest signal strength.