3,4-Diaminotoluene is primarily used as an intermediate in the production of dyes and pigments. It plays a key role in synthesizing azo dyes, which are widely used in the textile industry for coloring fabrics. Additionally, it is utilized in the manufacture of polymers and resins, contributing to the development of materials with enhanced durability and chemical resistance. In the field of organic synthesis, it serves as a building block for creating complex chemical compounds. Its applications also extend to the production of corrosion inhibitors, which are essential in protecting metal surfaces in industrial settings.