The document describes the design and development of an Internet of Things (IoT) based portable Geiger-Muller counter. The system consists of a Sparkfun Geiger counter board, NodeMCU microcontroller, and Blynk app for cloud services. Radiation levels are measured by the Geiger counter and sent via WiFi to the Blynk cloud server. The Blynk app stores and visualizes the radiation data in real-time on an Android mobile device. The system was tested in the laboratory and found to accurately measure radiation levels in agreement with standards.