Perovskite and organic photodiodes have emerged as promising candidates for ultraviolet–visible and near-infrared photodetection owing to their tunable optoelectronic properties, solution processability and potential for low-cost fabrication. This Review provides a comprehensive overview of the recent advancements in these technologies. We focus on the characterization methodologies critical for assessing device performance, particularly specific detectivity (D*), the key metric for benchmarking photodetectors. We highlight state-of-the-art devices, identifying their architectures, materials and performance metrics, while analysing their fundamental charge recombination processes and device-level factors limiting further improvement. Finally, we discuss future research directions and technological innovations necessary to bridge the gap between laboratory-scale devices and their practical utilization in real-world applications. Our aim is to provide a roadmap for advancing the field towards next-generation high-performance and commercially viable photodiodes for ultraviolet–visible and infrared detection.