Halogen, xenon or LED: how to tell if you have xenon headlights
The quickest way to tell is to switch the dipped beams on and look. Xenon (HID) headlights give a bright, bluish-white light that flickers and changes colour for a second or two as they start, and use bulbs with codes beginning with "D". Halogen headlights give a warmer, yellowish-white light the instant you switch on. LED headlights are crisp white, come on instantly, and usually have no bulb at all. Your handbook or your car's page will confirm which you have.
How can I tell if I have xenon headlights?
Look for these signs. One on its own isn't proof, but two or three together usually are.
| Clue | Halogen | Xenon (HID) | Factory LED |
|---|---|---|---|
| Colour of light | Warm, slightly yellow white | Bright white with a blue tinge | Crisp, pure white |
| At start-up | Full brightness instantly | Brief flicker, colour settles over a few seconds | Full brightness instantly |
| Inside the lamp | Visible bulb, often in a reflector bowl | Round projector lens | Small LED elements, often strips or shapes |
| Back of the lamp | Simple plug on the bulb | Ballast box and a thick connector | Sealed back, no bulb holder |
| Bulb code | H7, H4, H1, H11 and so on | Starts with D: D1S, D2S, D3S, D4S | None |
| Headlamp washers | Sometimes | Usually | Sometimes |
| Automatic levelling | Rarely | Usually (lamps move at start-up) | Often |
Some halogen headlamps use a projector lens too, so a lens alone doesn't mean xenon. And some halogen bulbs are coated to give a whiter light, so colour alone can mislead. The flicker at start-up and the "D" code are the most reliable signs.
What does the "D" bulb code mean?
Xenon bulbs use their own coding. The "D" marks a gas-discharge bulb, the number identifies the type, and the last letter tells you the lamp design: "S" for projector lamps and "R" for reflector lamps. D1S, D2S, D3S and D4S are common examples.
If your handbook's bulb table lists a D-coded bulb for the dipped beam, your car has xenon headlights in that version. Our guide to finding the bulb table in your handbook shows where to look.
How do I know if my headlights are LED?
Factory LED headlights normally have no replaceable bulb. Look for groups of small square LED elements behind the lens, light strips or distinctive shapes, and a sealed back to the lamp with no dust cap or bulb holder.
Of the 360 UK car generations we've verified, 43 have a factory LED dipped beam. The Renault Clio V is one: both dipped and main beam are LED and non-replaceable. If your LED headlight fails, see what to do when a non-replaceable LED fails.
Be careful with cars where LED daytime running lights sit next to a halogen headlamp. A bright LED strip doesn't mean the dipped beam is LED. The Ford Kuga Mk3 is a good example: LED daytime running lights, but an H7 halogen dipped beam.
Why does the headlight type change which bulb I need?
Because halogen, xenon and LED lamps are completely different systems:
- Halogen takes a standard bulb such as
H7orH4. Of the generations we've verified, 201 useH7for the dipped beam and 74 useH4. Our guide to H7, H4 and H1 explains those. - Xenon takes a D-coded discharge bulb with a different base and a high-voltage supply. A halogen bulb won't fit, and nor will the reverse.
- LED usually takes nothing: the fix for a failure is a lamp unit or module.
The same generation of car can come with more than one type. Lower trims often have halogen, while higher trims or option packs get xenon or LED. That is why our car pages split the headlamp entry by lamp type where the manufacturer offered more than one. If you see a split, use the clues above to pick the right line.
Can I convert halogen headlights to xenon or LED?
Not with a bulb swap. The MOT inspection manual, section 4.1.4, means a halogen headlamp unit converted to HID or LED bulbs is a fail on vehicles first used on or after 1 April 1986. Factory-fitted xenon and LED units are fine. The MOT inspection manual has the full wording, and our guide on whether LED headlight bulbs are legal explains it in plain English.
If you want more light from halogen headlamps, an uprated halogen bulb of the correct code is the legal route.
Can I change a xenon bulb myself?
We'd advise against it. Xenon lamps run at very high voltage when they start, and the ballast can hold a charge. Changing a xenon bulb is a job for a garage or dealer. Some cars also need the lamp access panel or bumper removed to reach it.
Halogen bulbs are a different matter: on many cars they are a straightforward home job. See how to change a headlight bulb.
Check your car
These pages show the headlamp bulbs for each generation, with any split by lamp type and the source we checked against:
- Ford Fiesta Mk7 bulbs —
H7dipped,H1main - VW Golf Mk7 bulbs —
H7dipped,H15main - BMW 3 Series F30 bulbs —
H7dipped and main - Ford Kuga Mk3 bulbs —
H7dipped with LED daytime running lights - Renault Clio V bulbs — LED, non-replaceable
Not listed? Browse all bulb pages or find your make.
Common questions
Are xenon and HID the same thing?
Yes. HID stands for high-intensity discharge, and xenon is the gas used in the bulb, so the two terms are used for the same type of headlamp.
Do xenon headlights always have washers?
Not always, but factory xenon headlamps usually come with headlamp washers and automatic levelling to keep the beam clean and correctly aimed. If your car has both, that is a strong hint it has xenon or LED headlamps.
My headlights look blue. Are they xenon?
Not necessarily. Some halogen bulbs are made to give a whiter, slightly blue-tinted light. Check for the start-up flicker and the bulb code before deciding.
Does my registration document say what headlights I have?
Not usually. Your handbook, the original specification or a dealer checking your vehicle identification number are better sources. Knowing your trim level and which generation your car is also helps.
Checked against our verification rules. Spotted something wrong? Tell us.