A composition includes a first compound represented by Formula 1 and a second compound represented by Formula 2. A light-emitting device includes the two compounds, a first electrode, a second electrode facing the first electrode, and an interlayer including an emission layer, and an electronic apparatus and electronic equipment each including the light-emitting device. The triplet (T1) energy levels of the two compounds are configured such that the luminescence efficiency and lifetime of the light-emitting device may be enhanced or improved.