Size: L: 15 cm. Wt: 18-19 g. Males and females are similar.
Adult: upperparts deep blue, with long, pointed wings, and a deeply forked tail with long streamers; underparts cinnamon, with dark, broken breast-band; bill small, black; legs dark brown
Juvenile: upperparts dark blue-grey, with some white edging on feathers, and no tail streamers; underparts buffy to pale cinnamon, breast band grey; bill and legs as in adult
Nestling: altricial and downy; grey down on head and back is long and sparse; mouth lemon yellow; gape flanges whitish