Earthquakes are a major threat to buildings and infrastructure, causing widespread damage and loss of life. Seismic design of buildings is crucial to minimize damage and ensure structural integrity during earthquakes. Traditional seismic design methods focus on strengthening the building to resist seismic forces, but this approach can be costly and may not always be effective. In recent years, researchers have been exploring alternative seismic design strategies, including the use of base isolators. This study presents a comprehensive seismic performance analysis of multistoried buildings equipped with Ni–Ti Shape Memory Alloy (SMA) base isolators. The primary objective of this research is to investigate the effectiveness of Ni–Ti SMA base isolators in mitigating seismic damage and improving the stability of multistoried buildings. A comparative analysis is conducted between multistoried building with and without a base isolator, evaluating the time period, displacement, acceleration, and base shear of the building. The numerical models are developed using ETABs, and the seismic performance is evaluated using response spectrum analysis. The results show that the Ni–Ti SMA base isolator significantly reduces the seismic response of the building, improving its stability and safety. The study demonstrates the effectiveness of Ni–Ti SMA base isolators in reducing the seismic demand on multistoried buildings, and highlights their potential as a viable seismic protection strategy.