The Van de Graaff (VDG) generator is ubiquitous in the physics laboratory, but the high-voltage discharges that emanate from it can cause user discomfort or damage to nearby electronics during experimentation. In this work, an augmented reality (AR) tool is developed to help students conduct the experiment safely. More specifically, it allows them to observe and investigate the discharge characteristics as a function of distance between the charged metallic sphere of the VDG generator and the spherical wand. The tool is shown to work well, and the feedback from students on its use was positive.