The concept of Industry 4.0 has now become a fact. One of its key technological solutions – the digital twin – serves as a bridge between the real and virtual worlds. Designs for both products and tools to make these products are generated in the virtual world. Thanks to the simulation capabilities of these digital replicas, it is possible to eliminate design flaws well before the creation of physical prototypes. Thus, the question naturally arises as to what degree these mathematical models of objects, processes or services replicate their physical counterparts. A correctly generated digital twin is not only a model or visualisation of its counterpart; it also reflects its dynamic behaviour. The issue of digital twins is a very broad one, and currently on the market, there are appearing an increasing number of tools available for the development of these twins. More and more often, 3D modelling software can be integrated with a control system model, facilitating the testing of newly designed objects in the virtual world. This paper presents the concept of building simplified digital twins in a web application environment. In addition to educational usage, the presented idea should find application in the design of small production lines, significantly affecting the cost of producing a digital twin.