One of the most famous descriptions of Mozart comes from his friend, the composer Johann Baptist Cramer. Cramer wrote that Mozart was "of a small stature, thin, and pale, with a longish face; small, piercing blue eyes; and a profusion of light hair. His countenance was rather stern and serious, but when he smiled there was a peculiar sweetness and benevolence in it."
Another description of Mozart comes from his sister, Maria Anna. She wrote that Mozart was "small and thin, with a large head and a long neck. His hair was light brown and curly. His eyes were blue and his nose was long. He had a small mouth and a chin that was slightly pointed."
Finally, there is a description of Mozart from the doctor who attended him during his final illness. The doctor wrote that Mozart was "of a short stature, with a well-proportioned head and a delicate frame. His hair was a light brown, and his eyes were a deep blue. His nose was long and thin, and his chin was small and pointed. His upper lip was slightly longer than his lower lip, and he had a pronounced Adam's apple."
Overall, it seems clear that Mozart was a small, delicate man with a pale complexion, blue eyes, and light brown hair. He had a long, thin nose, a small, pointed chin, and a pronounced Adam's apple.