LED car lights.jpg

What are LED headlights and how do they work?

A headlight is a device that’s used to light the road ahead of a vehicle. There are many different types of headlights with varying functions, so over the next week we’ll be looking at three different types of car headlights that are currently available: LED headlights, Xenon headlights and Halogen headlights. With LED headlights for cars becoming more common, this article from Auto Express explains how they work and some of their pros and cons.

Most people know that LED stands for Light Emitting Diode, however, less realise LED car headlight units can bring an increase in cost and complexity over halogen bulbs, and also an increase efficiency and adjustability – thanks in part to the diminutive proportions and power usage of each diode.

Most new cars come with LED daytime running lights, but full LED headlights are not industry standard (yet). As manufacturers chase reduced fuel consumption and lower emissions, easing the electrical strain on a car has become more important, and that is exactly what LED lights help do.

They produce crystal clear light, which when combined with matrix light technology (explained later) offer huge advances in adaptability and illuminating power over standard LED, xenon and halogen headlamps. A negative to the LED units, especially of the matrix kind, is replacing the unit can be incredibly costly.

That being said, full LED headlights are likely to keep increasing in prevalence and spending the extra money might be an advantage down the line come sale time. Also, if you are less than confident when driving at night, LED matrix lights could go a long way to helping you.

How do LED lights work?

An LED is simply a semiconductor which emits light when a current is passed through it – they only work with current flowing in one direction, mind. Due to requiring relatively little current to illuminate, the energy drawn from the battery (and therefore the engine) is less than halogens and xenons.

Current flows from cathode to anode passing through a semiconducting material, which is a material which had a conductivity somewhere between metal and rubber, made by adding a material that conducts electricity to an insulating material. The semiconductor then emits photons, which then illuminates the road ahead.  

Toyota Corolla - headlight

Due to the simplicity of the LED, there is very little to go wrong with them, which is why they are predicted to last well over a decade. That said, LED headlights haven’t been around long enough to establish how long they will last for when used on the open road.

What are adaptive LED lights

It is worth noting not all adaptive headlights are LED units. An adaptive unit is merely a headlight which can change its direction and/or brightness to suit road conditions – whether that be older halogen units, more modern LED ones, or industry leading laser units.

More articles like this

If you’ve found this article useful, you might also be interested in a previous article which provides a complete guide on when to use car lights to keep safe on the road.

Read the article

An adaptive LED light is one that is both made from LEDs and able to change its direction and or brightness.

What are LED Matrix lights and how do they work?

In mathematics, a matrix is defined as a rectangular array of numbers organised in rows and columns which are treated as a single entity. Swap out ‘numbers’ for ‘LEDs and mirrors’ in that definition and you should be able to imagine, as a rough concept, what an LED matrix headlight is.

LED matrix headlights work by teaming a collection of LEDs and mirrors with a collection of sensors and camera(s). The latter scan the road ahead to identify traffic and changes in road conditions – such as a sharp turn.

They then use this data to illuminate, dim or even turn off each LED within the matrix, with the ultimate goal of keeping as much of the road lit up with the maximum amount of light. Because of these attributes, matrix LED lights are also referred to as adaptive lights.

LED headlight pros and cons


  • Energy efficient
  • Can be relatively inexpensive
  • Long predicted lifetime


  • Can be complex  
  • Can be incredibly expensive

This article was written by James Wilson from Auto Express and was legally licensed through the NewsCred publisher network. Please direct all licensing questions to legal@newscred.com.

Related articles 

When to use car lights: The complete guide

Fog lights and when to use them

What are dipped headlights and when should you use them?


From the Motability Scheme


Popular articles