Perovskite LEDs are an emerging technology for next-generation display, lighting and communications. While perovskite LEDs can be produced simply and at low cost, they show clear technological advantages. They are lightweight and offer flexibility comparable to OLEDs, and they have color purity and tunability similar to LEDs based on III-V semiconductors. With only a few years of research performed by scientists around the world, the efficiency of perovskite LEDs already rivals more mature technologies.