The current work aims to study the magnetic field on mixed convection heat transfer with Casson fluid flow over a porous medium in the presence of the thermo-diffusion mechanisms with CNTs. CNTs have a wide range of industrial, biomedical, energy production, and space cooling applications because they can improve the thermal properties of the base material. A non-linear governing equation is mapped to a set of ordinary differential equations via a similarity transformation. The highlight of the work is the Casson fluid using CNTs over a Darcy porous media through momentum and temperature profile with the support of an analytical process. The various plots are also used to discuss the effects of physical parameters such as Casson fluid; mass transpiration, Darcy number, and Dufour-Soret number on the profiles, which are depicted through graphical representations. Modulating temperature distribution in different industrial applications, including solar collector design, electronic cooling, building ventilation, etc. The study reveals that the thermal radiation, Casson fluid; mass transpiration, Darcy number, Dufour-Soret number, Lewis number, and Prandtl number increase the values of Richardson number, also buoyancy ratio, magnetic parameter, and volume fraction decrease the values of buoyancy ratio, also controls the transfer of heat. Studies are done on boundary effect studies that have an impact on fluid flow. The behavior of physical factors, such as the Lewis, Prandtl, Dufour, and Soret numbers influencing temperature and concentration field, is determined and presented using graphs. Highlights The analytical method is used to executive equations are converted in the highly non-linear ODEs are obtained from PDEs. The importance of SWCNTs and MWCNTs in modifying MHD, Richardson number, Buoyancy ratio Casson nanofluid parameter and Heat source/sink, carbon nanofluid flow is examined. Stretching/shrinking sheet under the impact of Magnetic parameter, Prandtl number, and mass transpiration non-Newtonian heating is considered. Water is a base fluid mixed with SWCNTs and MWCNTs. The impact of magnetic parameter, Casson fluid, Darcy number, Lewis number, Dufour number, Soret number, mass transpiration, and nanoparticle volume fraction parameter studied.