In the seafood industry, shrimp is quite popular because of its delicious taste and great nutritional content. Shrimp spoils quickly because of the high levels of free amino acids, water, and nonnitrogenous chemicals necessary for microbial metabolism and because of the melanosis that gives it its distinctive dark color. Several factors contribute to the rapid deterioration of harvested shrimp, including autolysis (the action of endogenous proteinases during shrimp storage), the proliferation of spoilage microbes, the breakdown of adenosine triphosphate (ATP), the synthesis of melanin, and the oxidation of lipids. One of the primary causes of unpleasant odors during shrimp spoiling is total volatile basic nitrogen, a byproduct of microorganisms. For market sellers and exporters, keeping control of shrimp’s freshness is essential. Estimating the freshness of shrimp using conventional methods is both costly and out of reach for most people. Sensors are characterized by their rapid response time, high sensitivity, exceptional selectivity, and convenient portability for detecting food toxins without the need for costly instruments, trained personnel, pretreatment of samples, or a lengthy detection time. In recent years, significant advancements have been made in the field of sensor technology for assessing the freshness of shrimp. Various types of sensors and indicators, including colorimetric pH indicators, fluorescence sensors, electronic noses, and biosensors, have demonstrated notable progress in this domain. Other novel methods, including hyperspectral imaging and Raman spectroscopy, are promising approaches to determine the spoilage/freshness of the shrimp. This chapter discusses novel methods to detect shrimp freshness, outlining their underlying concepts and sensitivities.