The Himalayan swiftlet (Aerodramus brevirostris) is a small swift. It is a common colonial breeder in the Himalayas and Southeast Asia. Some populations are migratory.
This swiftlet was formerly placed in the genus Collocalia. Two of its five subspecies are frequently given full species status, A. b. rogersi as the Indochinese swiftlet, Aerodramus rogersi, and the isolated Javan form A. b. vulcanorum as the Volcano swiftlet, Aerodramus vulcanorum.
This 13–14 cm long swiftlet has swept-back wings that resemble a crescent or a boomerang. The body is slender, and the tail is forked. It is, in many respects, a typical swift, having narrow wings for fast flight, and a wide gape and small beak surrounded by bristles for catching insects in flight. Its legs are very short, preventing the bird from perching, but allowing it to cling to vertical surfaces.
It is mainly grey-brown above and paler brown below. It has a pale grey rump and a pale patch above and behind the bill. The sexes are similar, but the juvenile has a less distinct rump.