3,5-Difluorophenylhydrazine hydrochloride is primarily utilized in organic synthesis as a key intermediate for the preparation of various heterocyclic compounds. It is particularly valuable in the synthesis of indole derivatives, which are important structures in pharmaceuticals and agrochemicals. The compound is also employed in the development of dyes and pigments due to its ability to form stable azo compounds. Additionally, it finds application in research laboratories for studying hydrazine-based reactions and mechanisms, contributing to advancements in medicinal chemistry and material science.