Sodium 2-Nitroaniline-4-sulfonate is primarily used as an intermediate in the synthesis of dyes and pigments. It plays a crucial role in the production of azo dyes, which are widely utilized in the textile industry for coloring fabrics. Its sulfonate group enhances water solubility, making it suitable for dyeing processes that require aqueous solutions. Additionally, it is employed in the manufacture of colorants for paper, leather, and inks. In research, it serves as a reagent for studying chemical reactions and developing new dye compounds. Its applications also extend to analytical chemistry, where it is used as a marker or standard in various tests.