Gas turbines are widely used engines in various industrial and aviation applications, serving as efficient source of power generation. Their compact size, efficiency, and ability to operate on a variety of fuels have made them essential in the electric power and aerospace industries. Gas turbines provide a huge opportunity for emission control through utilizing hydrogen fuel as an alternative energy source. Hence, in the present study, the opportunity to change to hydrogen fuel will be utilized and a performance impact will be analyzed to understand the gas turbine behavior. To undertake the objective, off-design simulation and validation will be carried out on SGT500 designed to operate at 19.1 MW. The simulation will be undertaken using the GasTurb12 software and the results are validated with a reference model. The model is then simulated for off-design of the same validated model on hydrogen fuel. The performance variation by changing the fuel type is then analyzed to assess the benefits and feasibility of using hydrogen as a fuel for the gas turbine. It was deduced from the results that hydrogen fuel can improve power output, thermal efficiency, heat rate, and fuel flow by 7.7%, 1.8%, 1.7%, and 58% respectively. It also increases turbine inlet turbine exhaust temperature (TET) and reduce surge margin