A GaN charger is a USB charger built using gallium nitride, a semiconductor material, instead of the traditional silicon used in older power adapters. Gallium nitride allows the internal electronics to switch more efficiently at higher frequencies, which lets manufacturers shrink the size of the charger considerably.
Because a GaN charger generates less waste heat for a given power output than an equivalent silicon based design, it can be built noticeably smaller and lighter while still delivering high wattage, which is why many multi port Power Delivery chargers capable of powering a laptop and phone at once are now built around GaN.
GaN describes the internal technology rather than a different charging standard, so a GaN charger still relies on USB Power Delivery or similar protocols to actually negotiate power with a connected device. See our USB charger guide for more on choosing one.
