In this study, a theoretical investigation employing the Wien2k package within DFT framework was conducted to inspect mechanical, structural, and optoelectronic properties of silver-based cubic chloro-perovskites QAgCl3. Stability of these compounds was confirmed by fitting optimized data to Birch Muranghan equation, enthalpy of formation and tolerance factor. The mBJ potential was utilized to compute band profiles, revealing semiconducting nature mainly from Ag d-states and Cl p-states. Born-Huang criteria confirmed mechanical stability, while other elastic parameters indicated ionic bonding, anisotropy, stiffness, ductility, fracture resistance, and bond-bending resistance. Optical study suggested suitability for practical optoelectronic devices, with a lack of absorbance in the visible region. These outcomes offer a platform for further experimental and theoretical research.