Air quality index is one of the major factors that thrives to maintain a sustainable eco-biological system. Inevitable factors like urbanization, industry revolution, and the rapid growth in the usage of fossil fuel-based transit system is adversely affecting the quality of air in the form of injecting toxic gases into the atmosphere causes a certain health issue for the human and livestock in the developing countries. Mezzanine technologies like Artificial Intelligence (AI), Machine learning (ML), Internet of Things (IoT) gives a promising solution in monitoring and measuring the air quality. Here an IoT based system is designed using a gas detecting sensor MQ-135 and relevant peripherals, on sensing the harmful gases an alert notification is received from the IoT operating device in the form of buzzer and the quality index of air in parts per million (PPM) will be displayed on the Liquid-crystal display (LCD). Prototype was developed and the test results are validated with the Tinkercad simulation platform results.