Many industrial and thermal systems regard continuous thermal propagation as vital because it may improve the efficacy of thermal engineering machinery and engines. Consequently, this is a potential development for bettering power energy through employing magnetized nanomolecules within a heat-carrying non-Newtonian fluid. This study examines nanofluids with Casson and Maxwell nanofluids by considering nonlinear radiation and heat generation because of bioconvection over a stretchable surface with a porous material. Moreover, the interaction between gyrotactic microorganisms and activation energy has been discussed in detail. The flow model under consideration is formulated via Thermophoretic diffusion and Brownian motion. Using similarity conversions, the regulating partial differential equations (PDEs) are made dimensionless, thus reducing them to ordinary differential equations. A shooting technique was employed to solve the problem; MATLAB software used RK methods combined with the shooting method to solve this problem. Many diagrams have been depicted to describe the diverse flow factors; other interesting quantities, such as motile microbes’ density and Sherwood numbers, are computed and plotted. In addition, mixed convection, buoyancy ratio, bioconvection Rayleigh constant, and resistivity due to magnetized significantly affect velocity profile through Casson–Maxwell nanofluid. It is seen that both Casson and Maxwell fluids have nonuniform boundary layers of temperature and concentration fields. Maxwell fluids’ temperature and concentration fields are more sensitive than Casson fluids toward the same parameters.