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If you are like many people who are wondering if tail lights and brake lights are the same bulbs (because one of them went out and you don’t know which one), the best answer to this question is a bit vague and short; “it depends on the vehicle”.

Brake lights and tail lights have the same location, but it is usually NOT the same light bulb. If your vehicle is using a double filament bulb, it is technically the same light bulb, but each filament is on a different circuit.

This means if your tail lights went out and brake lights did not, the lamp would only respond when you press your brake pedal and vise versa. You can check what these lamps look like in the picture below:

The thin filament is used for the tail light and the thicker filament (which renders a stronger light), is used for the brake light. Their design and construction have been also changing as new lighting technologies improve.

Here is a nice video on how to diagnose and repair tail or brake light:

Tail lights vs brake lights

If you are asking this question, I would assume that you know the difference between the tail light and brake light. But just in case, I will state it in a brief introduction.

Vehicles have one tail light on each side. Their purpose is to ensure that the vehicle is clearly visible from the rear end.

The world convention about these lights is that they have to be “red” so that when other drivers are seeing them on, they will know that the vehicle is going in the same direction as they are.

With time, as vehicles became faster, the size and intensity of the rear end lights became bigger and brighter. Now, with the introduction of LED technology, the taillights continue to become brighter but not necessarily bigger.

The brake lights function to alert the drivers of other vehicles about the vehicle in front of slowing down. It is very important to know if the driver ahead of you is hitting breaks, to avoid accidents.

How these lightbulbs were invented

At the beginning of car history, cars had only tail lights. Brake lights were invented around 1905, but they were not mandatory to be placed on vehicles.

With time, different countries and their states started to require brake lights to be installed as a standard on every new vehicle model that was launched to the market.


In the early 1900s, cars had one bulb for each light, but then, with the invention of the double filament bulb in the 1920s, car manufacturers could have both lights in a single lamp, though the circuit for the activation of each filament is independent.

Having two separate filaments means that they can also be burnt independently. You could have, for example, your brake light working fine, but your tail light burnt.

The minimal amount of brightness that each light must have is specified by the different authorities that make vehicle regulations. But in general, these regulations have been standardized worldwide in a way that is more practical for vehicle manufacturers to launch a product in different regions at the same time (and they can get approved faster).

In many instances, the tail light and brake light are located on the same double filament bulb. But some manufacturers, for the sake of efficiency and in search of more interesting and appealing products, have been using as many light bulbs as they need to get a nicer look.

This means that you may have the tail light and the brake light in separated light bulbs, as shown in the picture below:

Regular light bulbs are being replaced fast with LED technology these days. This technology is changing not only the vehicle’s looks but also making their lighting more efficient.

LED bulbs consume less power and are more beautiful than regular lights. These lamps are also sealed, so they don’t have user-serviceable parts inside.

LED bulbs are more technologically advanced than regular light bulbs and they are supposed to last for the vehicle’s lifetime. They are also becoming more common in our day-to-day life and I am sure we are going to see a lot more of them in the future.

This article is for informational purposes ONLY and is NOT a replacement for professional advice!

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