Phorid flies are minute or small - 0.5–6 mm (1⁄64–1⁄4 in) in length. When viewed from the side, a pronounced hump to the thorax is seen. Their colours range from usually black or brown to more rarely yellow, orange, pale grey, and pale white. The head is usually rounded and in some species narrowed towards the vertex. The vertex is flat. In some species, the ocellar callus is swollen and highly raised above the surface of the vertex. The eyes are dichoptic in both males and females (eyes of males close-set, of females wide-set). The third segment of the antenna is large and rounded or elongated, and bears a long apical or dorsal arista directed sideways.