The development of online motorcycle taxi transportation has received a good response in the community. With this application, it makes it easier for people to order motorbike taxis more practically. Many online motorcycle taxi drivers have complaints while working, one of which is the obligation to meet life's necessities which causes the physical and mental workload to increase. This study aims to measure the physical and mental workload of online motorcycle taxi drivers in Serang City. Data collection was carried out by measuring heart rate with a Polar H10 and filling out the NASA-TLX questionnaire which was distributed to online motorcycle taxi drivers who were willing to be respondents. Data processing starts from measuring heart rate, with an average %CVL value obtained of 40.08%. This value is included in the physical workload category that requires improvement. For mental workload data on online motorcycle taxi drivers, the average obtained from calculations using the NASA-TLX method is in the high category, namely 74.20. The suggestions given to reduce these two workloads are calculating work break times with a duration of 90 minutes, designing extra footsteps for automatic motorbikes, using sprayable energy, facilitating road congestion detection tools, improving the quality of online motorcycle taxi applications, and reducing heat stress exposure.