<p>Superalloys have played a prominent role, particularly in aerospace applications, for the past few decades. The present investigation examines the oxidation resistance of Ni-based superalloys at 1200&#xa0;°C under isothermal high-temperature environment. The oxidation resistance and kinetics of three distinct Ni-based superalloys—Inconel-718, Haynes-230, and XH60BT—were investigated using electrochemical impedance spectroscopy (EIS). A detailed understanding of oxidation kinetics was explored by phase and chemical analysis using x-ray diffraction and x-ray photoelectron spectroscopy (XPS). The surface morphology of oxide products, including tetragonal, biaxial pyramids, flakes, and polygonal plates, was identified using scanning electron microscopy (SEM). The growth of oxide layer over time was studied by energy-dispersive x-ray spectroscopy (EDS), and mechanical property is analyzed using of Vickers hardness testing. According to the EIS data, the charge transfer resistance (<i>R</i>_<i>ct</i>) values vary over time based on the alloy’s composition and oxide growth kinetics. The highest <i>R</i>_<i>ct</i> is observed in Inconel-718 as 206 MΩ as oxide layer growth and highest oxidation resistance is observed in XH60BT as lowest <i>R</i>_<i>ct</i> with small variation in the mechanical strength due to high-temperature oxidation HVN in range of 272-227.</p> Graphical Abstract <p></p>