In order to carry out the usability and validation studies, a product prototype is being prepared, and its aim is to have the highest possible visual similarity and good operation resemblance to the final product. The work on the product prototype begins with the creation of the entire prototype structure, and then individual screens are prototyped in detail. Usually, however, the entire functionality of the product is not covered — only the flow for the individual personas that we want to check during the tests. When usability tests are carried out to validate a new concept, the product prototype becomes a useful tool. It is characterized by click rate and as much as possible visual similarity to a real product. It is supposed to pretend to be a real product so that during the tests the subjects feel free to use it. Most often, however, the product prototype does not cover all functions of the designed system, only the solution's spirit and the main paths on which future users will move. Although the implementation of an interactive product prototype requires a bit more work than static screens, finally its use allows to save on production costs. The required corrections indicated by usability tests are applied to the project before it is implemented. However, the product prototype role does not have to be limited to usability testing only. It may also help stakeholders to understand designed solutions or be used during presentations aimed at attracting investors. Prototyping accompanies inventions from the beginning of time and is equally effective in creating digital products.