This study investigates the impact of forward facing step height on shock boundary layer interactions in Mach 6 flow through both experimental and numerical simulation approaches. The results reveal that the separation length significantly increases for laminar flow simulations on a forward facing step with a 11 mm height compared to turbulent separation. The increment in the separation length is more than double the size of the turbulent separation and plateau pressure is 50% of the turbulent separation. However, for a step with a height of 22 mm, the plateau pressure is nearly equivalent to turbulent separation, when separation occurs at the leading edge. Both configurations showed the low frequency (102–103) unsteady shock oscillations, and they are similar to other canonical forms.