Abstract Designing adsorption processes requires knowledge of the adsorption isotherms. Measuring accurate isotherms is time consuming and inefficient equidistant points are usually chosen. Here, we combine isotherm measurements with Model-Based Design of Experiments to iteratively determine isotherm models with less experimental effort, while maintaining high model accuracy. Our joint approach combining isotherm model discrimination and parameter precision is validated by thermo-gravimetric experiments for the adsorption pairs Lewatit VP OC 1065 with $$\textrm{CO}_2$$ and $$\textrm{H}_2\textrm{O}$$ and BAM-P109 with $$\textrm{H}_2\textrm{O}$$ , covering isotherm Types I, III, and V. Results show that the experimental effort could be reduced between 70–81%. Furthermore, the framework scheduled measurements for Lewatit VP OC 1065/ $$\textrm{H}_2\textrm{O}$$ to discriminate its isotherm Type between II or III, devoid of our bias as experimenters. Overall, our approach demonstrates potential to streamline the identification of adsorption isotherms while enabling more efficient and unbiased model development.