This research endeavor investigates the natural convection flow of Williamson fluid in the region between two vertical parallel flat plates via porous medium. Impacts of viscous dissipation, joule heating, exponential space-and thermal-dependent heat sources (ESHS/THS) are invoked. Mass transfer is also studied accounting chemical reaction impact. The governing non-linear PDEs are reduced to ODEs in non-dimensional form under adequate transformation relations. The numerical technique, namely, Runge–Kutta fourth-order is utilized to tackle the problem with shooting method. Additionally, second law analysis is presented in terms of entropy production. The effects of numerous regulating parameters occurred in the problem relevant to flow, heat and mass transport, and entropy production are discussed via graphical mode of representation. Moreover, the quantities of physical significance are computed, displayed in graphical form, and discussed. For verification of acquired results, a comparison is also made using HPM with prior research and found to be in excellent agreement. It is concluded that the fluid temperature field enhances with upsurging values of pertinent parameters. The influence of the convective surface parameter and order of reaction are found to make augmentation in mass diffusion. Further, effect of Joule heating is noticed to rise rate of heat transfer while reverse scenario observed with upsurging values of heat source parameters. The influence of viscous dissipation is seen to grow entropy production.