Croconic acid disodium salt is primarily used in analytical chemistry as a reagent for the detection and quantification of metal ions, particularly in complexometric titrations. Its ability to form stable complexes with various metals makes it valuable in water treatment processes to remove heavy metal contaminants. In the field of dye-sensitized solar cells, it serves as an electrolyte additive to enhance performance and stability. Additionally, it is employed in organic synthesis as a building block for the preparation of specialized organic compounds, including dyes and pigments. Its unique chemical properties also make it useful in research for studying coordination chemistry and redox reactions.