Sodium 4-Aminoazobenzene-4'-sulfonate is primarily used as a dye in various industries, particularly in textiles for coloring fabrics. Its vibrant color and stability make it suitable for dyeing natural and synthetic fibers. Additionally, it is employed in analytical chemistry as a reagent for detecting specific ions or compounds. Its application extends to the production of inks and coatings, where it contributes to color consistency and durability.