Squaraines, a celebrated class of organic dyes known for their remarkable photophysical properties, particularly fluorescence behaviour in the near infrared (NIR) region, have emerged as versatile molecular tools in the domain of biophotonics. They offer unparalleled opportunities for molecular sensing, bioimaging and theranostics. This review delves into the unique capabilities of these dyes, spotlighting advances in design and functionalization that enable their application across diverse biol