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 Land Rover Defender Sport: baby SUV hedges bets with EV and hybrid power
New baby Land Rover Defender render - watermarked

New Land Rover Defender Sport: baby SUV hedges bets with EV and hybrid power

The new Land Rover Defender Sport will sit below the existing Defender in both size and price, and our exclusive image previews how it could look
News
17 Jun 2026
New BMW i3 on sale now: electric 3 Series finally ready to take on Tesla Model 3
BMW i3 50 xDrive - front 3/4

New BMW i3 on sale now: electric 3 Series finally ready to take on Tesla Model 3

Are you watching Tesla, Polestar, Audi and Mercedes? The new BMW i3 is here setting new standards with its huge 563-mile range
News
18 Jun 2026
New Honda Super-N 2026 review: little EV is fun and full of character
Honda Super-N and Richard Ingram

New Honda Super-N 2026 review: little EV is fun and full of character

Honda's quirky Super-N is compromised on paper, but in reality it's a fun and efficient small EV
Road tests
19 Jun 2026

Find a car with the experts