They visibly differ from the other swifts in matters of plumage, which is softer, and they have crests or other facial ornaments, and long, forked tails.

[1] Anatomically they are separated from the true swifts by skeletal details in the cranium and palate, the anatomy of the tarsus, and a nonreversible hind toe that is used for perching on branches (an activity in which true swifts are unable to engage).

They also have diastataxic wings, that is they lack a fifth secondary feather unlike swifts in the Apodini, which are eutaxic.

Highly manoeuvrable, it feeds close to vegetation beneath the canopy, and only rarely ventures into secondary forests or plantations, but never over open ground.

Chicks hatch with a covering of grey down and are fed a bolus of regurgitated food by the parents.