Skip advert
Advertisement

What are halogen headlights and how do they work?

We explain what halogen headlights are and how they work to keep you safe at night

Halogen headlights are named after a group of gas elements (the halogens) which are used inside them. In a bulb, the primary function of a halogen gas is 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 decade. 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.

Advertisement - Article continues below

Best headlight bulbs

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

Pros

  • • Cheap
  • • Easy to replace in the event of failure

Cons

  • • Poor energy efficiency, impacting economy
  • • Life cycle not as long as LEDs are predicted to last

Enjoyed this tips and advice article? Then take a read of our piece investigating night time driving glasses.

Skip advert
Advertisement
Skip advert
Advertisement

Most Popular

Dacia Spring EV updated for 2026, and it’s still got a tiny price tag
Dacia Spring facelift - front

Dacia Spring EV updated for 2026, and it’s still got a tiny price tag

The Dacia Spring has been improved for 2026, but a replacement could come soon
News
16 Dec 2025
New Jaguar GT ride review: is the controversial luxury EV a proper Jaaaaag?
Jaguar GT 2025 - front tracking

New Jaguar GT ride review: is the controversial luxury EV a proper Jaaaaag?

100mph-plus sprint round test track reveals a comfortable, high-performance GT with plenty of promise and true Jag credentials.
Road tests
17 Dec 2025
All-new Ford Fiesta previewed in this week's special Auto Express
Auto Express 1,912

All-new Ford Fiesta previewed in this week's special Auto Express

In Auto Express magazine this week, we have exclusive images of the new Ford Fiesta and get a first taste of the Jaguar GT
News
17 Dec 2025