What is an inverter microwave, and is it better?

An inverter microwave varies the power of the magnetron continuously, rather than switching it fully on and off — and that difference is genuinely audible, visible in results, and worth understanding before paying more for one.

How a conventional microwave does power levels. The magnetron has essentially one setting: full power. "50% power" means running at full power for half the time, cycling on and off — perhaps twenty seconds on, twenty off. You can hear the change in pitch as it cycles.

Why that causes problems:

During the on phases, the food is being cooked at full power, so edges overheat while the centre is still cold.

During the off phases, heat conducts inward — which is genuinely how conventional defrosting works, and why it is slow and uneven.

Melting chocolate, softening butter, warming milk and defrosting are the tasks where cycling shows most, because they need gentle, continuous heat rather than alternating bursts.

What an inverter does. A power supply that actually delivers reduced continuous power to the magnetron. At 50% the magnetron runs continuously at half strength.

The genuine benefits:

More even results at low power settings — noticeably better defrosting and gentler reheating without rubbery edges.

Better texture for delicate tasks.

A more consistent sound, without the cycling drone.

Slightly more usable interior in some models, since inverter power supplies are more compact than the heavy transformer they replace, and the appliance is lighter.

The honest limits:

No advantage at full power. Boiling water, reheating a plate of leftovers or cooking a jacket potato at 100% is identical — most microwave use is at full power, where the technology does nothing.

Not faster. Power output is what determines speed, and that is unchanged.

Repairability is worse in some cases, and inverter boards can be a costly component.

Whether to pay more depends entirely on whether you actually use low power settings. If you defrost and gently reheat regularly, yes. If you press the 30-second button, no.