As tadpoles, Pacific treefrongs consume a variety of aquatic invertebrates and detritus. They mostly feed on algae, bacteria, and floating vegetative debris. Adults primarily consume terrestrial invertebrates, with only 4.8% of their diet coming from aquatic sources. Adults usually feed at night on invertebrate species, often consuming great quantities of flying insects. During breeding season, adults may feed during the day. Adults capture insects by extending their tongues. The tongue is coated by a sticky secretion that traps the insect, along with any debris or dirt near the insect. Food items are typically swallowed whole.

Animal Foods: insects; terrestrial non-insect arthropods

Plant Foods: algae

Other Foods: detritus ; microbes

Primary Diet: carnivore (Insectivore ); herbivore (Algivore)