Active filter circuits are a crucial topic in electrical, electronics and signal processing education, but their complexity often poses significant challenges to traditional classroom teaching. Virtual labs provide an immersive and interactive learning experience without the need for costly equipment and materials, offering a solution to these challenges. In this research paper, the approach to designing and implementing a virtual laboratory of active filter circuits using JavaScript is presented. The lab includes a breadboard, function generator, multi-meter, and uses a simulation engine to calculate voltage and frequency values in circuits. The virtual lab was evaluated through user research with engineering and science students, and it was found to be highly effective in teaching active filter circuits. Virtual labs are an essential tool in engineering education, providing increased flexibility and reduced costs.