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

New Citroen 2CV: icon to be reborn for the electric era, and it’s coming soon
Citroen 2CV exclusive image 2026

New Citroen 2CV: icon to be reborn for the electric era, and it’s coming soon

The planets are aligned! Retro design buzz and rules promoting small EVs will see Citroen's most famous car rebooted
News
30 Mar 2026
Kia EV2 review
Alastair Crooks with the Kia EV2

Kia EV2 review

Cool styling, an efficient powertrain, surprising space - the Kia EV2 is a solid new entry in the small EV market
In-depth reviews
1 Apr 2026
New Renault Twingo 2026 review: a brilliant electric city car
Jordan Katsianis with the Renault Twingo

New Renault Twingo 2026 review: a brilliant electric city car

The new Renault Twingo EV is clever, good-looking and a delight to drive
Road tests
31 Mar 2026

Find a car with the experts