The article provides a comprehensive review of inorganic photochromic materials, highlighting recent advances, mechanisms, and emerging applications. Photochromic materials, which exhibit reversible color changes upon exposure to light, have gained significant attention due to their potential in various applications such as smart windows, optical memories, and anti-counterfeiting. The review covers the development of high-performance photochromic materials, the underlying physical mechanisms, and techniques for evaluating and controlling photochromic behavior. Key aspects discussed include: 1. **Material Advances**: The review covers different types of inorganic photochromic materials, including robust oxides, rare earth (RE) doped compounds, transition metal oxides, and metal halides. 2. **Mechanisms of Photochromism**: Detailed explanations of the photochromic processes in various materials, such as the formation of F-centers in robust oxides, photoinduced electron transfer in RE-doped compounds, and redox reactions in transition metal oxides. 3. **Evaluation Techniques**: Techniques for characterizing photochromic behavior, including optical spectroscopy, EPR spectroscopy, X-ray photoelectron spectroscopy (XPS), and micromorphological characterization. 4. **Emerging Applications**: The application of photochromic materials in optical information storage, photocatalysis, optical anti-counterfeiting, and radiation dosimetry. 5. **Challenges and Future Directions**: Challenges in achieving large photochromic contrast, color-tunable response, and detailed understanding of photochromic processes, along with perspectives for future research. The review aims to provide a fundamental understanding of the mechanisms, properties, and applications of inorganic photochromic materials, promoting their use in various optical devices.The article provides a comprehensive review of inorganic photochromic materials, highlighting recent advances, mechanisms, and emerging applications. Photochromic materials, which exhibit reversible color changes upon exposure to light, have gained significant attention due to their potential in various applications such as smart windows, optical memories, and anti-counterfeiting. The review covers the development of high-performance photochromic materials, the underlying physical mechanisms, and techniques for evaluating and controlling photochromic behavior. Key aspects discussed include: 1. **Material Advances**: The review covers different types of inorganic photochromic materials, including robust oxides, rare earth (RE) doped compounds, transition metal oxides, and metal halides. 2. **Mechanisms of Photochromism**: Detailed explanations of the photochromic processes in various materials, such as the formation of F-centers in robust oxides, photoinduced electron transfer in RE-doped compounds, and redox reactions in transition metal oxides. 3. **Evaluation Techniques**: Techniques for characterizing photochromic behavior, including optical spectroscopy, EPR spectroscopy, X-ray photoelectron spectroscopy (XPS), and micromorphological characterization. 4. **Emerging Applications**: The application of photochromic materials in optical information storage, photocatalysis, optical anti-counterfeiting, and radiation dosimetry. 5. **Challenges and Future Directions**: Challenges in achieving large photochromic contrast, color-tunable response, and detailed understanding of photochromic processes, along with perspectives for future research. The review aims to provide a fundamental understanding of the mechanisms, properties, and applications of inorganic photochromic materials, promoting their use in various optical devices.