The current review describes advances in the use of fluorescent 2,1,3‐benzothiadiazole (BTD) derivatives after nearly one decade since the first description of bioimaging experiments using this class of fluorogenic dyes. The review describes the use of BTD‐containing fluorophores applied as, inter alia, bioprobes for imaging cell nuclei, mitochondria, lipid droplets, sensors, markers for proteins and related events, biological processes and activities, lysosomes, plasma membranes, multicellular models, and animals. A number of physicochemical and photophysical properties commonly observed for BTD fluorogenic structures are also described. [ABSTRACT FROM AUTHOR]