The sopranissimo or soprillo saxophone is the smallest member of the saxophone family. It is pitched in one octave above the soprano saxophone, although the keywork only extends to a written high E rather than F. Due to its small size, the upper octave key has to be placed in the mouthpiece. It is difficult to build an instrument so small, and only recently has a true sopranissimo saxophone been produced. The soprillo is 12 inches in length (13 inches with the mouthpiece).
Because it is so small and requires such a small and focused embouchure, the soprillo is difficult to play, particularly in its upper register. Additionally, the market demand for soprillos is comparatively small, so the economy of scale is reduced, thereby making a soprillo more expensive relative to other, larger saxophones such as the alto or tenor.