Brownian motions and Thermophoresis are primary sources of nanoparticle diffusion in nanofluids, having substantial implications for the thermo-physical characteristics of nanofluids. With such a high need, the two-dimensional, laminar MHD quadratic convective stream of Carreau-Yasuda nano liquid across the stretchy sheet has been reported. The flow is caused by surface stretching. The principal purpose of this extensive study is to enhance thermal transmission. The effects of variable thermal conductivity and heat source are considered as well. The governing boundary layer equations are transmuted using similarity parameters into a series of nonlinear ODEs. The bvp4c algorithm is adopted to fix the translated system numerically. The effects of prominent similarity variables over the temperature, velocity, and concentration field are graphically visualized and verified via tables. It explored that fluid’s speed diminishes for the more significant inputs of the magnetic coefficient, Brownian motion coefficient, and Prandtl number. The thermal efficiency is improved for larger values of thermophoretic constant, varying thermal conductance, and heat-generating parameters. The concentration field has proved to be a decreasing function of nanofluid constants.