Stimulus-responsive materials are fundamental to the broad and ever-growing field of intelligence research, which bridge intelligent systems with the Internet of Things (IoT) in future lifestyles. Among these materials, writable materials have received great interest; however, carbonization and irreversible writing processes are generally inevitable for extensively investigated organic compounds. Photochromism is a potential mode of composing information. Nevertheless, inorganic materials usually exhibit weak photochromic effects. Here, a novel strategy of designing high-entropy perovskite (HEP) oxides is put forward to develop a new inorganic photochromic system with satisfying performance. A series of HEP oxides are synthesized for the first time. Benefiting from excellent photochromic features, real-time information encoding was achieved. The mechanism-related photochromism is also discussed. Distinct from the previous works, it is believed that the present photochromic-based HEP oxides provide a new and manyfold research space for the future development of conventional writable materials and the disclosing of unprecedented properties and phenomena.