The performance of traffic lights often encounters issues such as lights being out or other malfunctions, which can result in erratic traffic patterns and even total gridlock at the same intersection, potentially leading to accidents among drivers. Therefore, it is crucial to design a monitoring system for traffic light malfunctions using the Blynk application based on IoT ESP32. This system aims to facilitate technicians in monitoring the condition of traffic lights in case of malfunctions across all lanes. It utilizes an ESP32 microcontroller, LED lights or traffic lights, resistors as converters, and the Blynk application as a monitoring tool. From the testing of the prototype device, it was found that the average values for red light were ADC 1.367, voltage 1.10 volts, and current 5.01 mA. For yellow light, the values were ADC 1.265, voltage 1.02 volts, and current 4.63 mA. As for green light, the values were ADC 1.283, voltage 1.03 volts, and current 4.70 mA. The average delays for red, yellow, and green lights were 2 seconds, 2 seconds, and 5 seconds respectively, with the green light flashing three times for 0.5 seconds each time for all lanes.