Present-day power systems have highly complex and stressed operating conditions owing to insufficient reactive power to meet the required power demand. This leads to increased real power and reactive power losses, as well as voltage instability within a power system. To achieve the flexible operation of the power system, Flexible Alternating Current Transmission System (FACTS) devices have been employed. The optimal location of FACTS devices influences the system's performance and significantly affects line/bus reactive power flows. Consequently, the line or bus voltage profiles have been improved, leading to a reduction in power losses. Particle Swarm Optimization (PSO) heuristic methods and HFPSO Hybrid heuristic methods have been used to identify the weakest bus/branch for the suitable placement of UPFC devices, improving voltage stability. This paper discusses a more significant reduction in power losses in a MATLAB environment. Flexible Alternating Current Transmission System (FACTS) devices address reactive power challenges in power systems and enhance operational flexibility. Strategic placement using Particle Swarm Optimization (PSO) and HFPSO Hybrid methods identifies weak points, optimizing Unified Power Flow Controller (UPFC) placement for improved voltage stability. UPFC integration strategically reduces real and reactive power losses, improving power transmission efficiency. This enhances line and bus voltage profiles, addressing instability and significantly reducing overall power losses. The paper offers a detailed analysis of the power system, highlighting the synergy between FACTS devices, heuristic optimization, and power loss reduction. Simulations in MATLAB validate the proposed methodology, demonstrating a noteworthy improvement in power system performance.