Polymorphing hydrogels can morph into another structure on demand with reprogrammable features. This concept extends the degree of morphing beyond that of traditional shape-morphing hydrogels, which predetermine their morphing capabilities at the fabrication stage. However, current polymorphing hydrogels face limitations due to the need for complex, non-sustained responsiveness or additional chemical steps for reconfigurable morphing. Here, photo-reactive DNA-cross-linked polymorphing hydrogels are presented that enable polymorphing under patterned light. The photo-reactive DNA cross-links act as a regulator in changing the shapes of the hydrogels by adjusting the lengths of the cross-links depending on the wavelength of light, which allows precise and dynamic morphing in a programmable way through a one-pot reaction. The high programmability involving spatiotemporal controllability and reprogrammable features offers advanced solutions for multifunctional soft machines and applications requiring complex processes.