Hydration and dispersion are the two most common problems encounter in shale formation. These problems eventually give rise to some serious wellbore instability issues, which are difficult to handle through conventional mud systems. The application of nanotechnology has now provided some inimitable solution to those integrity issues. In the current study, for the first time comparison between activated carbon and silica coated iron oxide nanoparticles in terms of filtration and shale stability is reported. Limited literature is available for both these entities; therefore focus was primarily on these particles. Both the particles were added in water-base mud system in two different concentrations of (0.25�0.50) wt that are equivalent to 0.875�1.75 g respectively. Result reveals that the effect of high concentration of activated carbon was effective in terms of reducing the loss of filtrate volume from the mud system. Furthermore, thin and smooth filter cake was obtained for both samples of nanoparticles and high weight percent samples of activated carbon. Moreover, both the samples of activated carbon demonstrate better shale inhibition characteristics. After an immersion test, the recovered shale sample from activated carbon exhibits less erosion and cracks on its outer surface. On the contrary, a larger quantity of salt deposition on the shale surface was witnessed in the nanoparticle sample. In addition, shale samples behave more hydrophobic under the influence of activated carbon. This hydrophobicity increases as the concentration of activated carbon increases in the mud system. The results of filtration and immersion tests were also modeled using the image processing technique in order to validate all the findings of this study. © The Author(s), under exclusive licence to the Institute of Chemistry, Slovak Academy of Sciences 2024.