Modern downdraft gasifiers used commercially are predominantly tailored for efficiently converting woody biomass, such as wood chips. However, substantial value also lies in the utilization of wood residues and Municipal Solid Waste (MSW), which are often underexploited. For gasifiers to serve a wider range of applications effectively, they must be capable of handling diverse waste inputs and adjusting their operation in real-time to suit varying material characteristics. This study centers on the advancement of a tar-free gasification system capable of processing MSW with high flexibility. The investigation outlines the systematic approach taken in designing, developing, and assessing the performance of this innovative gasifier. The core focus of the technology is to convert MSW into usable thermal energy through gasification. The prototype developed in this work features a square-shaped stratified fixed-bed downdraft gasifier, engineered to process up to 10 kg of feedstock per hour. It accommodates both pelletized and non-pelletized forms of MSW, offering versatility in input types. During experimental trials, the highest volume of producer gas 38 m³/h. was recorded in the third trial phase, which utilized a balanced mixture of wood and MSW in equal proportions. This setup also yielded the highest calorific value of gas, calculated at 1250 kcal/Nm³. By integrating advanced thermal flare systems that efficiently combust the produced gas, the developed gasifier significantly reduces thermal energy production costs. Furthermore, analyses of the mass and energy distribution confirmed an efficient and consistent relationship between the fuel input and the energy output, validating the system’s operational effectiveness.