In a conventional incandescent lamp the tungsten particles which evaporate from the hot filament are carried by convection current to the relatively cool bulb wall where they accumulate and form a black deposit. In a tungsten-halogen lamps, with burning temperatures of several hundred degrees centigrade, the tungsten atoms and halogen gas particles, typically bromine vapor, combine to form tungsten-bromide  . As long as the envelope temperature exceeds 250°C, the tungsten-bromide will not adhere to the hot envelope. When the tungsten-bromide reaches the hot filament, the compound breaks apart into tungsten and bromine vapors. The tungsten is redeposited onto the filament, while the bromine vapor reenters the regenerative cycle  . This cycle keeps the envelope clean, enabling a much brighter light output throughout the lamp life.

Theoretically, the tungsten-halogen lamp life could be infinitely longer if the tungsten was redeposited evenly onto the filament. However, as redepositing is uneven, the lamp burns out when a thinner section ('hot spot') develops on the filament. Rated life of the tungsten-halogen lamp is much longer than that of regular incandescent lamps of equivalent wattage.
The quartz envelope, which can withstand extremely high temperatures, can be placed in close proximity to the filament, enabling a drastic reduction in the size of the bulb. This in turn enables the development of more sophisticated optical system based on a more condensed light source and a reduction in luminaire size.
 The high burning temperature of the filament of the tungsten-halogen lamp also results in a high color temperature, typically  between 3000 and 3400° K.