This moderately large North American frog is a wide-ranging species. The males are usually slightly smaller than the females. A pointed snout and flat head possessing two transverse rows of vomerine teeth are also observed. The toe pads on Hyla cinerea are large. The hind feet display extensive webbing and have two metatarsal tubercles between the toes. Some populations have individuals that lack lateral stripes, but normally H. cinerea exhibits a lateral white or yellow stripe from the jaw to the thigh on either side of the body. White or yellow spots are often scattered on the back. The external, subgular vocal sac is mostly white or yellow in males when not inflated. During breeding season, the sides of the sac may turn green.
The size of tadpoles ranges from 4.5-5.5 mm from hatching and may grow to 60 mm before metamorphosis in a 28-44 day span. Until tadpoles reach stage 25 or 26, they display continuous ontogenetic color changes. After this period, the body turns green and the venter turns yellow. The tail may have distinct yellow orbitonasal stripes, and dark mottling or reticulations. Large tadpoles sometimes retain the yellow interorbital stripe. A long tail, bulging lateral eyes, dextral anus and sinistral spiracle are other morphological features of the tadpole from this species.Adults of this species normally turn to an ashen gray color when in preservative. The normally unobserved dorsolateral stripes in living species also appear over the subcutaneous insertions of lymph-sac septa. After months in preservation, H. cinerea displays a mostly dark green or brownish color (Conant and Collins 1998).