What Are Dipped Beam Headlights?

What Are Dipped Beam Headlights?

When searching for the best headlight bulbs, you're bound to come across a variety of terms - dipped beam headlights, main beams, high beams, and low beams. These terms can be confusing, and many drivers don't actually know what they mean. In this article, we'll answer your questions about dipped beam headlights and other terms.

Dipped beam headlights

Dipped beam headlights are the headlights you use most of the time when driving at night. They're also referred to as low beams or just dipped headlights. These are quite possibly the most important lights on your car. Your dipped headlights, or dipped beams, will get a lot of use if you frequently drive in the dark at night.

Why are they called dipped beam headlights?

The term comes from the direction in which the light points. Whilst it may look like your dipped headlights point straight ahead, they're actually angled down towards the road. These headlights dip down to prevent you from blinding other drivers. If they were facing directly forward, they would be shining directly into the eyes of oncoming traffic.

Main beam

Your main beam is the brighter light you might use when driving on a country road at night. These are sometimes called high beams. As you may have guessed, these lights shine forward and up. This is perfect for driving on roads with no streetlights, where you need to illuminate the entire road.

However, you don't want to use your main beam lights in areas with heavy traffic. Because these lights shine straight ahead, they can cause glare for other drivers. When driving on a dark road with your main beams on, you should always dip your lights when another car is passing on the other side of the road. Don't use your main beam if someone is driving in front of you, either. The light can reflect off their rear and side view mirrors and can blind them.


Shop dipped beam and main beam headlight bulbs here.

Single and dual filament bulbs

In some vehicles, the dipped beam and main beam lights are two separate bulbs. They may be contained in the same headlight housing, but one bulb is for the dipped beam and the other is for the main. These are known as single filament bulbs, because each bulb has only one filament inside.

Other cars use dual filament bulbs (sometimes called twin filament). As the name suggests, these bulbs each contain two filaments. One is for the dipped beam, and the other for the main beam lights. This setup makes it a lot easier to replace headlight bulbs, as one bulb works for both purposes.

Most vehicles with a twin filament bulb use a H4 fitting. If your vehicle has any other type of headlight bulb fitting, it's most likely single filament.


Shop twin filament bulbs here.

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About the Author

John Conboy is the founder of, a UK based automotive lighting specialist, which ships bulbs worldwide. John has 20+ years experience in the industry and in that time has become an approved partner of Philips and OSRAM.