Magnetic tunnel junctions may experience failure due to local shortcuts in the insulating layers of such devices. To further develop magnetic tunnel junctions. the areal density of pinholes must be analyzed. By electrodepositing copper, we have developed a method to image pinholes and analyze the density of pinholes. Copper selectively nucleates at particular sites, forming structures that can be visualized using an optical microscope. Using this method, we examined the change in size of grown copper structures over time and the increase in the areal density of defects as a function of the applied electrodeposition potential.