The density functional has been implemented to deliberate the cubic perovskite XSnO3 (X = Ba, Sr) for their elastic, electronic, optical as well as thermoelectric characteristic. The XSnO3 (X = Ba, Sr) illustrates good pact of lattice parameter for these iso-structural compounds having cubic perovskite structure. The generalized gradient approximation based on the exchange-correlation functional is applied for computing structural and mechanical characteristic, whereas the electronic, optical and thermoelectric properties have been studied by the functional suggested by Tran and Blaha that is termed as of modified Becke-Johnson (mBJ) functional. The thermodynamics stability is recognized through the expression of enthalpies of formation, which is further verified from the calculated structural properties of cubic perovskite XSnO3 (X = Ba, Sr). Moreover, various elastic parameters such has bulk modules B, C-ij, shear modulus G, Young's modulus Y, anisotropy factor, BIG ratio and Poisson's ratio v have also been reported. It has been observed by band structure computation that the studied compounds exhibit an indirect band gap between the unoccupied Ba/Sr 6s/5s and the occupied O 2p orbitals. Detailed study of optical properties is presented under the incident photon energy upto 28 eV. Our computed static dielectric constant 82(0) and refractive index n(0) are comparable with other theoretical and experimental values. Thermoelectric properties are presented in terms of computed Seebeck coefficient, electrical and thermal conductivities and their variation with the rise in temperature suggest that the studied compounds may find applications in the construction of various thermo-electric devices. (C) 2017 Elsevier B.V. All rights reserved.