Harmful substances are mixed into the air to cause air pollution. The main issue facing every country, developed or developing, is air pollution. Particularly in urban regions of emerging countries, where industrialization and an increase in the number of cars lead to the discharge of several gaseous pollutants, health issues have been escalating more quickly. Humans are lowering the quality of the air in an effort to improve their standard of living. The health of people is fatally affected by the dispersed particles in the air. The usage of a MQ 135 gas sensor coupled with a node MCU as part of an IOT-based air pollution monitoring system is proposed. To analyse sensor data, the system is linked to the think speak cloud through an ESP8266 wifi module.The basic concept behind the suggested approach is the installation of a system in each car to ensure that emissions from each vehicle stay below a certain limit. The best way to combat issues like global warming may be an IOT-based approach.