Plasma televisions generally have superior picture quality, contrast and black levels as compared to similar LED-lit LCD televisions. However, LED televisions often have a brighter picture than plasma televisions, and LED televisions are substantially lighter and less power-hungry as well. A third type of LED television, known as an OLED television, is superior to either plasma or conventional LED televisions in almost all respects, but these televisions are usually very expensive.
Most LED televisions use liquid-crystal display technology as in older LCD televisions, but use light-emitting diodes to light the screen. In contrast, plasma televisions use individual bubbles of electrically excitable gas as pixels. Though many LED televisions use several LED light sources to provide lighting, they still are unable to control picture brightness on a per-pixel basis as is possible in plasma televisions. This is the primary reason that plasma televisions have superior contrast and deeper blacks than LED televisions, as the light from the LEDs leaks through the darkened pixels. However, a typical plasma display weighs twice as much and consumes twice as much electricity as an LED television of the same size.
Televisions that use OLED or organic light-emitting diode technology use LEDs themselves as the pixels of the display rather than liquid crystal display elements. This gives them many of the advantages of plasma displays, as they can light each pixel individually. However, the OLED technology is also much lighter and more energy-efficient compared to plasma displays.