There are four species in this family. Treeswifts are found in South and Southeast Asia, the islands of Southeast Asia and the western Pacific, and parts of northern Australia and New Guinea.

Treeswifts spend much of their time in the air. They are insect-eaters (insectivores) and catch insects while flying. They are most often seen in forests and woodlands, where they hunt above the treetops.

Unlike true swifts, treeswifts can perch on branches. They have long, pointed wings, forked tails, and many species have a small crest of feathers on their heads.

Treeswifts build small nests on tree branches. The female usually lays a single egg, and both parents help care for the young.