Rhacophorus baluensis inhabits montane forests of nothern Borneo.

It is a mid-sized (50–65 mm) frog with a general brown color in various shades. There are dark brown markings and small black spots on the dorsum, and banding on thigh and shank. The heel bears a spur. The fingers are at most half webbed; the toes are fully webbed.

Inger & Stuebing (2005) described the tadpole as large (75 mm), with slightly flattened, oval body. The tail is about two thirds of the total length and ends bluntly.