H7 vs H4 vs H1: which headlight bulb does your car use?
The difference between H7 vs H4 bulbs is the number of filaments. An H7 has one filament and does one job, usually dipped beam, while an H4 has two filaments and does dipped and main beam in one bulb. An H1 is another single-filament bulb, most often used for main beam alongside an H7 dipped beam. All three have different bases, so none of them will fit in place of another.
Of the 360 UK car generations we've verified, 201 use an H7 dipped beam and 74 use an H4. So the most likely answer for a mainstream car is H7, but you need to check your exact generation.
What is the difference between H7 and H4 bulbs?
An H7 is a 55 W single-filament bulb on a PX26d base. Cars that use it for dipped beam have a separate bulb for main beam, which might be another H7, an H1 or something else.
An H4 is a twin-filament bulb rated 60/55 W: 60 W for main beam and 55 W for dipped beam, on a larger P43t base. One bulb per side does both beams, so the headlamp only needs one main bulb.
H7 | H4 | H1 | |
|---|---|---|---|
| Filaments | One | Two (main + dipped) | One |
| Wattage | 55 W | 60/55 W | 55 W |
| Base | PX26d | P43t | P14.5s |
| Typical job | Dipped beam, sometimes main beam | Dipped and main beam together | Main beam |
| Dipped beam in our data | 201 generations | 74 generations | – |
| Main beam in our data | 89 generations | 73 generations | 56 generations |
The counts come from our verified rows only. They describe the cars we've checked, not every car on UK roads.
Can I use an H7 instead of an H4?
No. The bases are completely different shapes, the headlamp reflector is designed around one specific filament position, and an H7 has no second filament for the other beam. The same goes for swapping an H1 and an H7: they look similar at a glance but the base and connector are different.
Even if an adaptor made a different bulb fit, the beam pattern would be wrong. Headlamp aim and operation are part of every UK MOT, and a badly placed filament can scatter light and dazzle other drivers.
What is an H1 bulb used for?
In our data, H1 is mainly a main beam bulb. It does that job on 56 verified generations, typically paired with an H7 dipped beam, and it also turns up as a front fog bulb on 10. That's the setup on the Ford Fiesta Mk7, Fiesta Mk8, Focus Mk3, Peugeot 208 and Vauxhall Corsa D.
Because main beam gets far less use than dipped beam, the H1 tends to clock up fewer hours than the H7 on the same car. When your dipped beam fails, it's still worth checking main beam works on both sides.
Which cars use H7, H4 or H1?
Here's how a selection of verified generations split:
| Car | Dipped beam | Main beam |
|---|---|---|
| Ford Fiesta Mk7 2008–2017 | H7 | H1 |
| VW Polo 6R/6C 2009–2017 | H7 | H7 |
| Vauxhall Corsa E 2014–2019 | H7 | H7 |
| Hyundai i30 GD 2012–2017 | H7 | H7 |
| Nissan Juke F15 2010–2019 | H4 | H4 |
| Toyota Yaris XP130 2011–2020 | H4 | H4 |
| Hyundai i10 2nd gen 2013–2019 | H4 | H4 |
| Ford Transit Mk7 2006–2013 | H4 | H4 |
On an H4 car the same bulb appears in both columns because one bulb does both beams. On a car like the Polo, two separate H7 bulbs sit in each headlamp, one for each beam.
Not every car fits this pattern. The Nissan Qashqai J11 uses H11 dipped and HB3 main beam, the VW Golf Mk7 pairs an H7 with an H15 main beam bulb, and 43 of the generations we've verified have factory LED dipped beams with no bulb to change at all.
Is H7 or H4 brighter?
You can't choose between them, so brightness isn't really the question. Your headlamp is built for one type and only that type will fit. If you want more light, the legal route is a higher-performance halogen bulb with the same code as the original.
Fitting LED bulbs into a halogen headlamp is a different matter. A halogen unit converted to LED or HID bulbs is an MOT fail on cars first used from 1 April 1986; see are LED headlight bulbs legal in the UK.
How can I check which bulb my car has without removing it?
You have three options before you start taking anything apart:
- Check the handbook. The bulb table in the maintenance or technical section lists each headlamp bulb by code.
- Look up your generation. Each FitsMyCar car page shows the dipped and main beam bulb, with the source it was checked against.
- Look behind the headlamp. With the bonnet open, count the bulb covers and look at the connectors. An
H4normally has a three-terminal plug and one bulb per headlamp. Two separate covers or plugs usually means separate dipped and main beam bulbs.
The third method is a clue, not proof. Headlamp layouts vary, and the bulb can differ between halogen, xenon and LED versions of the same model. If you're not sure which headlamps you have, read halogen, xenon or LED: how to tell.
Check your car
Find your dipped and main beam bulbs by generation:
- Ford Fiesta Mk7 and Ford Focus Mk3
- VW Polo 6R/6C and VW Golf Mk7
- Vauxhall Corsa D and Vauxhall Corsa E
- Nissan Juke F15 and Toyota Yaris XP130
- Hyundai i10 2nd gen
Or browse every car on the bulbs page.
Common questions
Do H4 bulbs have two filaments?
Yes. An H4 has a main beam filament (60 W) and a dipped beam filament (55 W) in the same glass. If either filament fails, you replace the whole bulb.
Are H7 and H1 bulbs the same?
No. Both are 55 W single-filament bulbs, but the H7 uses a PX26d base and the H1 uses P14.5s. They won't fit each other's holders.
Should I change both H7 bulbs at once?
It's a good idea. The bulb on the other side has done the same hours and may not be far behind, and a matched pair gives even light. See should you replace headlight bulbs in pairs.
Why does my car have two H7 bulbs in each headlamp?
Some cars, including the VW Polo 6R/6C and Vauxhall Corsa E, use an H7 for dipped beam and a second H7 for main beam. They're the same bulb doing different jobs, so you only need to stock one type.
Checked against our verification rules. Spotted something wrong? Tell us.