We have investigated the stripe domain structure and the magnetic reversal of perpendicular Co/Pt based multilayers at room temperature using magnetometry, magnetic imaging and magnetic x-ray scattering. In-plane field cycling aligns the stripe domains along the field direction. In magnetic x-ray scattering the parallel stripe domains act as a magnetic grating resulting in observed Bragg reflections up to 5th order. We model the scattering profile to extract and quantify the domain as well as domain wall widths. Applying fields up to ~;1.2 kOe perpendicular to the film reversibly changes the relative width of up versus down domains while maintaining the overall stripe periodicity. Fields above 1.2 kOe introduce irreversible changes into the domain structure by contracting and finally annihilating individual stripe domains. We compare the current results with modeling and previous measurements of films with perpendicular anisotropy.