Can I swap an MR16 bulb for a GU10?

Not directly. GU10 is mains voltage and MR16 is low voltage with a different holder, so they are not interchangeable. Converting from one to the other means changing the fitting and wiring, which is a job for a licensed electrician.

Why does my MR16 LED flicker but the GU10 does not?

MR16 spotlights run through a transformer that may not be rated for LEDs, which is a common cause of flicker. GU10s run straight off mains power, so they avoid that particular problem.

Last updated: 19 August 2026

GU10 vs MR16 spotlights

GU10 and MR16 are the two common spotlight fittings — the little two-pin bulbs in downlights and track lights. They look almost identical, but they run on completely different voltages, which is why you can't simply swap one for the other.

The key difference: voltage

GU10 runs on mains voltage (230V). It has two chunky pins with rounded tips, and you push it in and twist a quarter-turn to lock — the "twist-lock" spotlight. Because it runs straight off mains power, there's no transformer involved.

MR16 runs on low voltage (usually 12V) through a transformer or driver. It has two thin straight pins that push into the holder. That transformer is the source of a lot of MR16 headaches — if it isn't rated for LEDs, the bulb can flicker.

How to tell them apart

	GU10	MR16
Voltage	Mains (230V)	Low (12V)
Pins	Two chunky, rounded tips	Two thin, straight
Fitting	Push & twist-lock	Push-fit
Transformer	None	Yes

Why you can't just swap them

Because the voltage and holder are different, a GU10 won't work in an MR16 fitting or vice versa. Converting a set of downlights from one to the other means changing the fittings and wiring — electrical work for a licensed electrician, not a DIY bulb swap. If you're only replacing the bulb, match what you already have.