The aim of this thesis is to conduct a comparison of two software tools for power flow analysis, DIgSilent PowerFactory and Pandapower, in order to determine their performance, accuracy, and user features. Power flow analysis is a crucial step in the planning and management of power systems, and the choice of the appropriate software tool can significantly impact the efficiency and reliability of the analysis. The thesis describes the entire development of both software tools, detailing their functions and capabilities, as well as their main advantages and disadvantages. For the DIgSilent PowerFactory software, five areas of application are listed and described: transmission, distribution, and generation of electricity, industry, and the integration of renewable energy sources. For the Pandapower software, the network models and data processing structure are highlighted and explained. In the practical part of the thesis, power flow analysis was conducted for a low-voltage distribution network, a medium-voltage distribution network, and a transmission network using both software tools. The results and comparison of the power flow analysis results are presented using tables and graphical representations to provide a clear and straightforward conclusion. The analysis results showed that both tools have their strengths and weaknesses, and the choice of tool for power flow analysis should be guided by the specific needs of the user, taking into account the type of analysis, system size, and the need for adaptability and integration with other systems.