Quelle est la différence entre GU10 et GU5.3 ?

Ce sont deux culots de spot qui ne fonctionnent pas sous la même tension. Le GU10 se branche directement sur le 230 V du logement, le GU5.3 sur du 12 V apporté par un transformateur. Le chiffre, lui, désigne l'écartement des broches en millimètres. Avant de choisir quoi que ce soit, on repère ce qui existe déjà au plafond : c'est le point de départ de tout projet d'éclairage pièce de vie .

Quel spot pour quelle pièce ?

Salle de bain et cuisine : un GU10 en IP44 minimum hors des volumes d'eau. Vitrine, niche et éclairage d'accent : un GU5.3 orientable, plus fin et plus discret. Plafond bas et couloir : un GU10 encastré à faible profondeur, espacé régulièrement pour éviter les zones d'ombre.

Spot GU10 : quelle puissance et quelle lumière ?

Un GU10 LED de 4 à 7 W suffit sous un plafond de 2,50 m. Comptez 5 W dans un couloir, 7 W dans une pièce de vie. Depuis le passage au LED, la puissance en watts ne dit plus rien de la lumière rendue : ce sont les lumens qui éclairent.

Peut-on remplacer un GU5.3 par un GU10 ?

Oui, à deux conditions : que le perçage accepte le nouveau spot et que le transformateur 12 V soit retiré. Un GU10 branché derrière un transformateur ne s'allume pas, ou clignote. Le perçage, lui, change souvent : environ 50 mm pour un GU5.3 contre 80 mm pour un GU10.

Spot fixe, orientable ou à variateur ?

Fixe pour un couloir ou une entrée, là où la lumière doit tomber droit. Orientable pour un plan de travail, une bibliothèque ou un tableau, afin de viser la surface utile. À variateur pour une pièce de vie : l'intensité se règle selon l'heure et l'usage.

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GU10 or GU5.3 spotlight: which to choose, room by room

This article is also available in French: Spot GU10 ou GU5 3

05/10/2026 · 9 min read · By the Designix team

Look for the transformer behind the spotlight, in the false ceiling or in the junction box. If there is one, the installation is 12 V and you need a GU5.3 base. If the spotlight is powered directly at 230 V, it is a GU10. This step settles the question before any order.

What is the difference between GU10 and GU5.3?

These are two spotlight bases that do not run on the same voltage. The GU10 connects directly to the 230 V of the home, the GU5.3 to 12 V supplied by a transformer. The number indicates the distance between the pins in millimetres. Before choosing anything, check what already exists in the ceiling: it is the starting point of any living room lighting project.

GU10 or GU5.3 spotlight: what really changes

	GU10 spotlight	GU5.3 spotlight
Supply voltage	230 V, directly on the mains	12 V most often, via a transformer
What the name means	G = base, U = shape, 10 = 10 mm between the pins	G = base, 5.3 = 5.3 mm between the pins
Pins	Two wide-head pins, locked with a quarter turn	Two thin pins, pushed straight in
Spotlight diameter	About 50 mm	About 50 mm, MR16 format
Transformer	None	Required to step down to 12 V
Typical use	Bathroom, kitchen, hallway, low ceiling	Display case, alcove, accent lighting
Replacing a halogen	Direct, same socket	Direct, but check the condition of the transformer
Dimming	Depends on the spotlight and the dimmer	Also depends on the transformer

What does GU actually mean?

GU means "pin base" and the number that follows gives the space between the two pins, in millimetres. Ten for a GU10, 5.3 for a GU5.3. The two look alike enough to be confused, although they are not interchangeable. Measuring the size of a bulb base takes ten seconds and saves a trip back to the shop.

It is often said that the GU10 is a bayonet base. That is incorrect: it locks with a quarter turn. A true bayonet base is pushed in and then twists onto two side lugs, which is quite different.

230 V on one side, 12 V on the other

The 230 V comes from the consumer unit and powers the GU10 with no intermediary. The 12 V passes through a transformer, housed in the false ceiling or in a surface-mounted box. A transformer at the end of its life causes flickering and sometimes switches off when turned back on.

Criterion	GU10	GU5.3
Voltage	230 V	12 V
Distance between pins	10 mm	5.3 mm
Transformer	No	Yes
Common recess diameter	About 80 mm	About 50 mm
Typical use	Hallway, kitchen, bathroom	Display case, alcove, slim furniture

Where the transformer hides

Look for a small box between the spotlight and the incoming line. Three locations come up most often.

In the false ceiling, a few tens of centimetres from the spotlight
In the junction box, on the incoming side of the circuit
In the fixture, on compact models with a built-in box

Which spotlight for which room?

Bathroom and kitchen: a GU10 in IP44 minimum outside the water zones. Display case, alcove and accent lighting: an adjustable GU5.3, slimmer and more discreet. Low ceiling and hallway: a shallow recessed GU10, evenly spaced to avoid shadow areas.

Bathroom and kitchen

In a bathroom, the spotlight must withstand humidity: IP44 minimum, IP65 above the shower. In a kitchen, an adjustable GU10 lights the worktop without casting the shadow of your hands. Both rooms are planned together in a kitchen and dining room renovation, with a ceiling lighting plan for moving around and a second one for working.

On the bulb side, reinforced protection is needed at points close to water: the selection of LED bulbs for bathrooms groups the models suited to this use.

Bulbs and spotlights with GU10 and GU5.3 bases

See the whole selection: LED bulbs: E27, E14, G9, GU10 | Designix

Display case, alcove and accent lighting

A GU5.3 fits into the slimmest fixtures, where a GU10 will not go. For a display case or an alcove, aim for a narrow beam and an adjustable spotlight: the light must fall on the object, not into the room.

Low ceiling and hallway

Under a 2.20 m ceiling, a shallow recessed spotlight avoids the "staircase" effect of spotlights that are too long. First work out the right number, with our guide on how many spotlights per m² depending on the height.

Then set the spacing, detailed in our article on the distance between ceiling spotlights. An even wash is better than one very bright point in the centre.

Once the room and the voltage are settled, only the bulb remains: our selection of GU10 bulbs covers 230 V, from the hallway to the bathroom.

GU10 spotlight: what power and what light?

A 4 to 7 W LED GU10 is enough under a 2.50 m ceiling. Allow 5 W in a hallway, 7 W in a living room. Since the switch to LED, power in watts no longer says anything about the light produced: it is lumens that light.

What is the power of a GU10 spotlight?

From 4 to 7 W in LED to replace a 35 to 50 W halogen. Replacing a halogen spotlight with an LED divides consumption by five or six, for the same light output.

The right reflex is still to read the specification in lumens, not in watts: our guide on bulb power for a living room gives the correspondences room by room.

Our bulb collection has 266 references as of 5 October 2026. On a sample of 32 of these references, recorded on the same date, 100% are LED and 100% are IP20; 72% are guaranteed 2 years and 28% 5 years. These shares apply to the sample, not to the whole collection.

Do 1000 lumens light well?

Yes, for a room of 8 to 10 m² or for two or three spotlights on the same ceiling. 1000 lumens correspond to an LED bulb of about 10 to 12 W. For 20 m², aim instead for 3000 to 4000 lumens spread over several points: 2000 lumens on a single spotlight becomes a lot for domestic use.

2700 K or 3000 K depending on the room?

2700 K for a bedroom or a living room: warm white light rests the eye in the evening. 3000 K for a kitchen, a hallway or a bathroom, whiter and easier to read on a worktop. Our comparison on warm or cool light details what each temperature changes in use.

If you go for neutral white, the 3000 K bulb collection groups the corresponding models, across all powers.

Can you replace a GU5.3 with a GU10?

Yes, on two conditions: that the cut-out accepts the new spotlight and that the 12 V transformer is removed. A GU10 connected behind a transformer will not light, or flickers. The cut-out, however, often changes: about 50 mm for a GU5.3 against 80 mm for a GU10.

What to do with the transformer

It is disconnected and removed. The GU10 is then connected directly to the 230 V supply, with a terminal block or a suitable connector. If you stay on 12 V, it is better to choose GU5 bulbs compatible with the transformer in place, some older models tolerate LEDs poorly.

Three things are not done: leaving the transformer upstream, mixing 12 V and 230 V on the same circuit, forcing a GU10 into a 50 mm cut-out.

The replacement, step by step

Switch off the circuit breaker and check that there is no voltage.
Unclip the spotlight, locate the transformer and disconnect it.
Connect the new GU10 spotlight to the 230 V, then put it back in place.
Switch back on and check that no point flickers.

The full procedure, with details of the fixing clips, is in our article on replacing a recessed GU10 spotlight.

You now know which base your ceiling requires: if you prefer us to check the survey with you before buying, our workshop answers in a few words, and you can talk to the workshop about your project.

Which spotlight to install in your home?

Fixed, adjustable or dimmable spotlight?

Fixed for a hallway or an entrance, where the light must fall straight. Adjustable for a worktop, a bookcase or a painting, to aim at the useful surface. Dimmable for a living room: the intensity is set according to the time and the use.

Fixed or adjustable spotlight?

A fixed one gives an even wash and costs less. An adjustable one is set after installation, which makes up for a badly placed wall or a moved piece of furniture. On a low ceiling, the adjustable one remains the most comfortable.

Do you need a dimmer?

It is not the spotlight that carries the function, it is the bulb. A dimmable spotlight requires a compatible bulb and a suitable dimmer, otherwise the light flickers or buzzes.

To check before buying, buyer reviews are available and permanently up to date on our Google listing.

Frequently asked questions about GU10 and GU5.3 spotlights

What is the difference between GU10 and GU5.3?

Both names refer to the distance between the pins, in millimetres: 10 mm for the GU10, 5.3 mm for the GU5.3. Above all, the GU10 connects directly to the 230 V, whereas the GU5.3 runs on 12 V and requires a transformer.

What is the equivalent bulb to a GU10?

The format is identical: a GU10 LED goes into the socket of a GU10 halogen without an adapter. What changes is the consumption stated in watts, much lower in LED for the same amount of light.

What is the difference between GU5.3 and MR16 bulbs?

MR16 describes the shape and diameter of the spotlight, about 50 mm; GU5.3 describes only its base with two thin pins. An MR16 format spotlight is almost always a GU5.3, but this format also exists in GU10.

What is the power of a GU10 spotlight?

It depends on the technology: a GU10 halogen called for a high power where a GU10 LED lights as much with much less. Look at the lumens and the colour temperature rather than the wattage shown.

Do 1000 lumens light well?

1000 lumens comfortably light a work area or a small room, but not a whole living room on their own. What decides is the total of the sources and the surface to be covered.