Mid-sized, generic-looking warbler-like bird. Males have a glossy blue-black back, a white wing patch, and pale yellowish underparts. Females are similar, but more gray-brown on the back. Found in savanna with broadleaf trees, including miombo and Guinea savanna. Usually in pairs or small groups, which will join mixed-species feeding flocks. The quiet vocalizations include chatty calls and trills. Very similar to Southern Hyliota. In most of the range, Yellow-bellied males distinguished by the longer white patch on the wing, and females by their grayer upperparts. In Uganda and Kenya, males are extremely similar, but Yellow-bellied can still be recognized by its more glossy blue-black back.