Polymeric gels, when made into thin films, are reported to depict a reversible folding behavior on exposure to favorable solvents as a result of the coupled diffusion–deformation mechanism. In this work, we develop a model based on the coupled diffusion–deformation mechanism which can predict the large deformation caused during this reversible folding behavior of a polymeric thin film. The formulation incorporates a concentration dependent Young's modulus variation. It is found that the incorporation of concentration dependent Young's modulus of the film in the formulation is essential to predict the folding curvatures accurately. The results obtained using this model are validated with the experimental results of the Chitosan–Water system by comparing the folding characteristics — intermediate folding stages and curvature, while accurately explaining the mechanism of reversible folding. The model is applied to other material systems such as PVA–Water and PDMS–Hexane systems. Furthermore, we demonstrate that the developed model successfully predicts the buckling and wrinkling phenomenon observed experimentally in stimuli-responsive polymer thin films. © 2020 Elsevier Ltd