Sodium 3-nitrobenzenesulfonate is primarily used as an intermediate in the synthesis of dyes and pigments, particularly in the production of azo dyes, which are widely employed in the textile industry for coloring fabrics. It also serves as a reagent in organic synthesis, aiding in the introduction of sulfonate groups into various chemical compounds. Additionally, it finds application in the preparation of specialty chemicals, including those used in the pharmaceutical and agrochemical sectors. Its role in analytical chemistry includes use as a standard or reference compound in certain testing procedures.