This swift has long, narrow wings and a deeply forked tail. It catches insects on the wing over highlands and builds a long, hanging tubular nest.
Adults are about 19–20.5 cm long. The body is dark, with a white throat and collar; white patches along the inner flight feathers show in flight. The tail is deeply forked, and the sexes and age classes look similar.
It is usually solitary and can glide for long periods without flapping. It makes a narrow tubular nest from plant material and saliva, hanging it from trees, cliffs, or walls with the entrance below.
An extinction-risk assessment has not been added yet.