SimplePhy is a Javascript-based tool that aims to make the design of experiments as simple as possible. This tool loads an experiment file with the configuration and location of the stimuli and runs the experiment in the same platform. Participant’s data is stored in a secure website and locked behind a password. The experimenter can download the data to analyze it. The PsyPhy tool is optimized for medical image perception experiments but it is also useful for other simple perception experiments such as MAFC and visual search.