What are halogen headlights and how do they work?

Halogen headlights are a more traditional choice for car headlights, but you do still find them in many new car models. This article from Auto Express explains what halogen headlights are and how they work and looks at some of the pros and cons of these lights.

Halogen headlights are named after a group of elements (the halogens) which are used inside them. In a bulb, the primary function of a halogen gas is to extend the life of the tungsten filament – but more on that later.  

They aren’t just popular in the automotive world, however, as they have been used in homes and street lamps for over half a century. That said, non-directional household halogen light bulbs are now banned in the EU due to their poor energy efficiency when compared to LED bulbs.

More about headlights?

There are some different options when it comes to car headlights, although it does depend on the type of car you have.

Find out more about LED headlights

Find out more about Xenon headlights

How do halogen lights work?

Halogens are one of the oldest types of bulbs you would expect to find on a new car sold in the UK. They work in a similar fashion to bulbs you would have seen in houses during the black and white times, meaning they consist of a glass bowl, filament and gas, and when current is passed through the filament it gives off light (and a large amount of heat).

They are called halogens as halogen gas is used to help prevent the tungsten filament being dumped on the glass and blackening the surface of the glass – meaning the bulb stays brighter for longer.

Halogen lights pros and cons


• Cheap

• Easy to replace in the event of failure



• Poor energy efficiency, impacting economy

• Life cycle not as long as LEDs are predicted to last


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.

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