A headlamp is a lamp connected to the front of a vehicle to illuminate the street ahead. Headlamps are also often known as headlights, however in essentially the most exact usage, headlamp is the time period for the system itself and headlight is the time period for the beam of light produced and distributed by the machine. Headlamp performance has steadily improved throughout the vehicle age, EcoLight energy spurred by the nice disparity between daytime and nighttime site visitors fatalities: the US Nationwide Highway Visitors Safety Administration states that nearly half of all site visitors-related fatalities happen at the hours of darkness, despite only 25% of visitors travelling throughout darkness. Different vehicles, comparable to trains and aircraft, are required to have headlamps. Bicycle headlamps are often used on bicycles, and are required in some jurisdictions. They can be powered by a battery or a small generator like a bottle or hub dynamo. The first horseless carriages used carriage lamps, which proved unsuitable for journey at pace.

The earliest lights used candles as the commonest type of fuel. The earliest headlamps, fuelled by combustible fuel akin to acetylene gas or oil, operated from the late 1880s. Acetylene fuel lamps have been fashionable in 1900s because the flame is resistant to wind and EcoLight rain. Thick concave mirrors mixed with magnifying lenses projected the acetylene flame mild. A variety of automobile manufacturers provided Prest-O-Lite calcium carbide acetylene gasoline generator cylinder with fuel feed pipes for lights as customary equipment for 1904 vehicles. The first electric headlamps were introduced in 1898 on the Columbia Electric Car from the Electric Vehicle Company of Hartford, Connecticut, and had been non-compulsory. Two factors restricted the widespread use of electric headlamps: the brief life of filaments in the tough automotive surroundings, and the problem of producing dynamos small enough, yet highly effective sufficient to supply enough current. Peerless made electric headlamps commonplace in 1908. A Birmingham, England agency referred to as Pockley Automobile Electric Lighting Syndicate marketed the world's first electric car-lights as a complete set in 1908, which consisted of headlamps, sidelamps, and tail lights that have been powered by an eight-volt battery.

In 1912 Cadillac integrated their automobile's Delco electrical ignition and lighting system, forming the trendy car electrical system. The Guide Lamp Firm introduced "dipping" (low-beam) headlamps in 1915, but the 1917 Cadillac system allowed the light to be dipped using a lever contained in the car slightly than requiring the driver to stop and get out. The 1924 Bilux bulb was the primary modern unit, having the sunshine for both low (dipped) and high (major) beams of a headlamp emitting from a single bulb. The same design was introduced in 1925 by Information Lamp referred to as the "Duplo". In 1927 the foot-operated dimmer swap or dip swap was launched and grew to become customary for much of the century. 1933-1934 Packards featured tri-beam headlamps, the bulbs having three filaments. From highest to lowest, the beams have been called "nation passing", "country driving" and "city driving". The 1934 Nash also used a three-beam system, though on this case with bulbs of the conventional two-filament sort, and the intermediate beam mixed low beam on the driver's aspect with excessive beam on the passenger's side, so as to maximise the view of the roadside whereas minimizing glare toward oncoming site visitors.

1952 "Autronic Eye" system automated the choice of excessive and low beams. Directional lighting, utilizing a change and electromagnetically shifted reflector to illuminate the curbside solely, was launched within the rare, EcoLight energy one-12 months-solely 1935 Tatra. Steering-linked lighting was featured on the 1947 Tucker Torpedo's middle-mounted headlight and EcoLight energy was later popularized by the Citroën DS. This made it potential to show the sunshine in the route of journey when the steering wheel turned. The standardized 7-inch (178 mm) spherical sealed-beam headlamp, one per aspect, was required for all vehicles bought within the United States from 1940, nearly freezing usable lighting technology in place until the 1970s for Americans. In 1957 the regulation changed to allow smaller 5.75-inch (146 mm) spherical sealed beams, two per side of the automobile, and in 1974 rectangular sealed beams had been permitted as effectively. Britain, Australia, and another Commonwealth international locations, in addition to Japan and Sweden, additionally made intensive use of 7-inch sealed beams, although they were not mandated as they were in the United States.