Smart bio-polymer films that offer shape transformation in response to stimuli have enormous potential ranging from soft actuators to biomedical applications as targeted drug release. Solvent triggered self-folding in polymer films results from the concentration gradient due to the diffusion of the solvent molecule across the film cross-section. Although there have been several studies on the self-folding behavior of synthetic polymer films, research on self-folding focuses largely on multi-components i.e., bilayer or multilayer system. In this contribution, we develop a novel approach for the fabrication of single-component soft bio-polymeric porous (spherical) poly(vinyl alcohol) (PVA) films that exhibit modular folding behavior in response to water. This approach is convenient, cost-effective, and moreover, the pore distribution in the polymer film can easily be controlled by adjusting film-forming variables. Our results indicate that the pore architecture in the films significantly enhances the actuation speed. A reversible, controlled, and predictable folding pathway is observed for the film with a critical porous layer thickness of ̴ 60% and above. While spherical porous film folds along the short-side the elongated (by means of mechanical stretching) porous film folds along the long-side of the film which folds permanently. Moreover, a detailed characterization of the shape changes during folding and its corresponding actuation speed is substantiated.