LED vs. Halogen vs. Xenon: Which Headlights Are The Best?

LED vs Halogen vs Xenon

Driving your car at night is only possible with the help of the right set of headlights to illuminate the road ahead. If you’ve already taken a cursory look at the headlight market, however, you’ll realize immediately that there are several different types of headlights.

Each type of headlight has a profile of advantages and disadvantages which you’ll need to consider before making a choice. In this article, we’ll take the time to explain each of the headlight types to you so that you will know which is the right set of headlights for your needs.

By the time you’re done reading, you’ll be an expert on headlights. Without further ado, let’s dive into the world of headlights with a discussion of the tried and tested halogen headlight.

How Halogen Lights Work

Halogen headlights are the most common on the market because of their low cost.

Halogen lights have a few components:

  • A dense metal filament which is typically made from tungsten
  • An inert gas
  • A small quantity of a halogen-class gas like iodine

Halogen lights work by passing an electric current through the tungsten filament which is surrounded by an inert gas. The inert gas contains small traces of halogen-class chemicals in the gaseous phase.

As a result of the electricity passing through the tungsten filament, the filament becomes extremely hot and emits light in conjunction with the gas surrounding the filament, vaporizing small portions of the outside of the filament.

Then, when the light is turned off, the presence of the halogen-class chemical allows for the evaporated tungsten to re-anneal onto the surface of the filament, preventing the filament from becoming degraded by repeated cycles of lighting.

There are several advantages to halogen lights. First, halogen lights are ubiquitous. The vast majority of vehicles on the road have halogen headlights. This fact means that halogen headlights are easy to replace if they become damaged.

Second, halogen lights are inexpensive. Because halogen headlights are tried and tested technology, they are produced at scale for pennies. You won’t break the bank by replacing your halogen lights.

Finally, halogen lights are technology with a lot of history. When a manufacturer lists the expected lifetime of a pair of halogen headlights, you can bet the farm on their estimate being extremely accurate because millions of halogen headlights have met that standard in the past.

Halogen headlights are far from perfect, however. In particular, there are several weaknesses to halogen headlights, including:

  • High heat emissions
  • Low light emissions relative to other headlight types
  • Non-configurable headlight color
  • Low durability
  • Limited lifespan

In the past, people have worked around these shortcomings by replacing their halogen headlights regularly, keeping their halogen headlights cool, and intelligently switching between using high-beams and standard headlamps to maximize the brightness of the light where it is needed the most.

Now that halogen headlamps are challenged by newer competitor technologies. However, there may be better options which use more sophisticated headlight technology.

How Xenon Lights Work

Xenon or HID headlights work similarly to halogen headlamps with a critical exception which makes a big difference.

Whereas halogen headlamps rely on a tungsten filament to light up and only use light emissions from the gas surrounding the filament as a secondary source of illumination, xenon headlights flip the equation and use the gas as the primary way to emit light.

In a xenon headlight, the components are similar to that of a halogen headlight. Xenon headlights have an inert gas, a pair of tungsten electrodes, and a small number of gaseous metals which emit light when excited by an electric current.

Instead of lighting the tungsten directly, xenon lights pass an electric arc between the two contacts of the tungsten electrodes. When the electric arc excites the gaseous metals and the inert gases, light is emitted.

Importantly, the amount of light emitted by the electric arc is far higher than the amount of light emitted by a halogen lamp’s passive excitation of the gas molecules surrounding the tungsten.

With a xenon lamp, the tungsten electrodes themselves also glow slightly, but it is not noticeable in comparison to the power of the electric arc’s light.

In vehicles, xenon headlights have a handful of advantages over halogen lights. These advantages include:

  • Massively higher brightness
  • Lower energy usage
  • Longer lifetime
  • Lower heat emissions
  • Faster warmup time
  • More color options

Each of these advantages is worth discussing. In comparison to halogen headlights, xenon headlights emit up to 45% more light per unit of electricity. This means that xenon headlights use less energy overall while also illuminating significantly more than halogen lights.

Furthermore, xenon headlights don’t degrade as rapidly as halogen headlights because the tungsten electrodes are not expected to be significant emitters of light.

Because the tungsten electrodes don’t bear any of the heat generated by the spark, they aren’t subject to repeated cycles of re-annealing of vaporized tungsten. In the long run, this means that xenon headlights wear out much slower.

Xenon headlights also don’t emit as much heat as halogen headlights, meaning that they are less likely to experience performance degradation over time. Importantly, xenon headlights even reach their peak brightness very rapidly after being turned on.

Halogen headlights typically require a period of five to ten minutes to reach their maximum brightness after being turned on because the tungsten filament needs to heat up. With xenon headlights, the inert gas inside the light is rapidly heated as a result of the electric arc.

Finally, xenon headlights have a plethora of color options which you can use to make them look more attractive. Halogen lights have no such diversity, and their yellow glow may be considerably less appealing than the pure white glow of default-configuration xenon lights.

How LED Lights Work

Light-emitting diodes (LEDs) are the rising star within the world of headlights as a result of their inexpensiveness and superior feature profile compared to legacy headlight technology.

LEDs are more straightforward than halogen light bulbs or xenon light bulbs. Rather than passing an electrical current through a combination of reliable components and gaseous components, LEDs translate electricity into light in one single step.

The way that LEDs accomplish this feat is by being semiconductors which leak excess energy in the form of light rather than heat.

In the context of LEDs, the semiconductors are typically made from gallium nitride with additional metals doped in for different colors. Current can only flow through the semiconductor at a specific frequency determined by the properties of the semiconductor.

When the frequency of the electric current is the same as the frequency permitted by the semiconductor, electricity can enter into the semiconductor and flow from its anode to its cathode.

Because the semiconductors used in LED lights are “leaky,” not all of the electrons moving through the semiconductor can make it from the anode to the cathode. Instead, some of these electrons escape through the semiconductors “electron holes” as light.

This light is subsequently what is channeled by mirrors in the headlight to illuminate the area in front of the car.

Many LED designs dope different metals into the semiconductor. These metals change the frequency at which the electrons can move through the semiconductor and therefore also modulate the frequency and color of the photons which leak out of the semiconductor.

While multicolor LEDs are not yet legal for use in vehicle headlights, this may change shortly and open the horizons for multicolored LED headlights which will be aesthetically pleasing to observe.

LED lights have a handful of advantages over the other headlight types, including:

  • A multitude of color options
  • High energy efficiency
  • Low cost
  • No warmup time
  • No heat emissions
  • No performance degradation at high or low temperatures

These advantages have made LEDs into powerful challengers within the headlight market. Many new headlights use LEDs when they might have used halogen designs in prior years. The technology behind LEDs is still in the process of maturing, however.

In comparison to halogen headlights, LED headlights are more expensive. In comparison to xenon headlights, LED headlights are often cheaper, but there are still a few inexpensive xenon headlights on the market.

In terms of their brightness, LEDs perform acceptably. LEDs may be brighter than halogen in some cases, but typically brightness is not their primary focus. Similarly, the brightest LEDs are nowhere near as bright as the dimmest xenon headlights.

Critically, LED lights are bright enough to illuminate the road. Thus, while they won’t win any awards for maximum illumination, they fulfill the requirements that most people have for their headlights.

Which Headlight Modality Is The Best?

The question of which headlight is the best for your car depends on your needs.

You should keep several factors in mind while evaluating each of these modalities, including your price sensitivity and your aesthetic sense.

The more sensitive you are to higher prices and higher maintenance costs, the more likely it is that you will be better served by an LED headlight. LED headlights are less expensive than xenon headlights in most cases.

Furthermore, LED headlights are only slightly more expensive than halogen headlights. Halogen headlights, however, tend to need replacement more frequently than LED headlights. Halogen headlights are also less durable than LED headlights.

LED headlights are not as bright as xenon headlights, nor are they as pure in terms of the color which they emit. In other words, LED headlights are not as flashy, and they are not traditionally as aesthetically pleasing as xenon headlights.

The difference in cost may make a xenon headlight worth it to you, however. If you are trying to choose between a replacement set of halogen headlights and a new set of xenon headlights, you will probably find that the xenon headlights are a good upgrade.

You should also keep in mind that LED lights would also be a good upgrade for halogen headlights, however.

Fanatics for brightness and pure coloration won’t be happy unless they have xenon headlights. These consumers will need to pay for the brightness and color options, however.

They’ll also need to look harder to find replacement parts and mechanics who are competent to replace their lights.

Overall, most consumers will have the best results with LED headlights. If you can find a pair of xenon headlights which are less expensive than LED headlights, however, you will probably be happy with them.

It’s important to remember that the price of LEDs will continue to drop for the foreseeable future. The same thing cannot be said about the cost of xenon lights or halogen lights.

This means that the price of replacing your xenon headlights five years from now will probably be higher than the cost of replacing LED lights that have the same sticker price today.

On the other hand, if you don’t want to gamble, the price of halogen headlights is likely to remain completely static for the foreseeable future. As a result, the price you pay for a halogen headlight today will likely be the same price you pay to replace them five years in the future.

Xenon headlights are not becoming less expensive as rapidly as LEDs are, nor are their features change as significantly as LEDs. LED lights will most likely become brighter and have more aesthetic options to choose from as time passes.

Lighting The Path Forward

Now that you know the differences between halogen, xenon, and LED headlights, it’s time to think about which type will be the right choice for your vehicle. As we mentioned previously, most people will find that LED lights serve their needs.

For hobbyists and fanatics, however, LED lights probably aren’t exclusive enough. Halogen lights simply won’t do, but the bright and pure white glow of xenon headlights continue to be eye-catching and desirable.

If you’re skeptical of new technology and you want to go with a tried and tested solution, halogen headlights are the best choice for you. On the other hand, if you’d rather pay an average amount to catch a bargain tomorrow, LED lights remain the best choice of the three.

Brett Gordon

The engine behind editing at DigMyRide and the brains behind its build. During the day, Brett is a thirty-something dude from SoCal climbing the corporate ladder, but by night, he spends his time contributing to the online world of automotive tech & trends.