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13 March 2025 (updated) H4 vs H7 headlight bulb: what is the difference and what does it mean?
Light and visibility are critical to your safety on the road. Nowadays, new cars have xenon or LED headlight bulbs. However, halogen lamps remain the most common type and can be found in around 80% of cars. They emit a high-intensity yellow-white light and are very cheap to produce. Common bulb fittings include H1, H3, H6, H4, and H7.
What is an H4 headlight bulb?
The term "H4" refers to dual-filament lamps, also known as bilux bulbs, meaning each bulb houses two filaments. This clever design enables a single bulb to function as both high and low beams, with one filament dedicated to each. Built for efficiency, H4 bulbs feature a single lamp base plate, making them a compact yet powerful lighting solution for various vehicles.
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What is an H7 headlight bulb?
H7 components are single-filament headlight bulbs. This means that you will need to install two H7 light bulbs per headlight, one for each beam. The reflectors are positioned according to the filament in each bulb. If your vehicle is compatible, it will have two base plates per headlight.
Philips offers LED headlight bulbs compatible with H4 and H7 lamp sockets. An LED Philips bulb will last much longer than halogen lamps: the H4 components can last up to 50,000 hours while H7 bulbs can last up to 30,000 hours. They are also waterproof and consume less power.
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What is the difference between H4 and H7 bulbs?
The H7 is a single filament bulb used for either high or low beams, while the H4 is a dual filament bulb used for both. H4 bulbs are more common in older vehicles and provide both types of light in a single unit. H7 bulbs, on the other hand, provide a more focused beam and are often found in modern cars. Be sure to check your vehicle handbook for compatibility before buying new bulbs.
It is impossible to replace an H4 bulb with an H7 one or vice versa as the differences are too great. There are two main reasons why they aren’t interchangeable:
- The type of base is different, so you can't fit the bulb into the socket of another bulb.
- The headlight reflectors are specifically designed to match the position of the bulb filaments. The positions are different for H4 and H7 bulbs, so this would affect the low and high beams.
|
Feature |
H4 Bulb |
H7 Bulb |
|
Design |
Dual-filament (high & low beam) |
Single-filament (either high or low beam) |
|
Light Function |
Provides both high and low beams in one bulb |
Separate bulbs for high and low beams |
|
Lumen Output |
1000–1500 lumens per filament |
1500–2000 lumens per bulb |
|
Power Consumption |
55/60 watts (low/high beam) |
55 watts per bulb |
|
Durability |
Lower durability due to dual-filament usage |
Higher durability (single filament) |
|
Application |
Older vehicles, motorcycles |
Newer vehicles, premium cars |
|
Price |
Generally cheaper (one bulb for both beams) |
Slightly more expensive (two bulbs needed) |
|
Installation |
Easier (one bulb per headlight) |
Slightly complex (two bulbs per headlight) |
|
Typical Usage |
Used in simpler headlight systems |
Common in modern, advanced lighting systems |
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What cars use an H4 headlight bulb?
Some popular manufacturers using H4 bulbs include Honda, Toyota, Mazda, Nissan, Subaru, and Volkswagen. These bulbs are versatile, serving both high and low beams in a single unit, making them suitable for various vehicles. They are commonly found in European models and are also used in motorcycles and some car models worldwide. H4 bulbs offer reliable lighting and are known for their dual-filament design, which enhances visibility without requiring additional wiring.
What cars use H7 bulbs?
H7 bulbs are used in a wide range of vehicles, including models from Audi, BMW, Mercedes-Benz, Volkswagen, Skoda and Nissan. Typically used for low beam in vehicles with separate high beam bulbs, they feature a single filament design that provides a consistent and focused beam pattern, making them ideal for low beam applications. H7 bulbs are particularly common in European models and can be found in cars such as the BMW 5 Series, Audi A3 and Volkswagen Golf. They are not interchangeable with bulbs such as H4 due to differences in the type of socket.
Can I use H7 instead of H4?
H4 and H7 bulbs are not interchangeable due to differences in base type and wattage. The H4 bulb has a dual filament design while the H7 has a single filament. These differences in design and function mean that they require specific sockets. The H4 socket is designed for its dual-filament structure, making it incompatible with an H7 bulb, which could lead to incorrect installation and potential safety hazards. It is therefore vital to use the correct type of bulb to ensure optimum performance and safety in your vehicle's lighting system.
What type of headlight bulb do you need?
The kind of headlight bulb required is determined by your vehicle’s make, model, and year. Consult your vehicle’s manual. Alternatively, you can check the existing bulb or use online look-up tools from auto parts stores. Popular options include H4, H7 and HID bulbs. Make sure you get the right match for proper installation and lighting performance, and remember to always check the correct bulb type for your vehicle before purchasing a replacement.
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