Levoit Core 400S

Levoit's large-room smart purifier with a True HEPA plus activated carbon cartridge, a PM2.5 air-quality sensor, auto mode, and Wi-Fi control through the VeSync app. Coverage of roughly 90 m² at one air change per hour is the largest single-room figure in this comparison, and the pure-HEPA design means no ionising by-products. Available widely at major online retailers. the combined HEPA-plus-carbon cartridge must be replaced as a single unit, so 24/7 use raises the annual filter cost; full smart features require a VeSync account and an internet connection; there is no humidifying function, so you will need a separate humidifier if dry winter air matters.

The Levoit Core 400S is the pick when you want the biggest single-room coverage with a connected app. Rated for roughly 90 m² at one air change per hour, it is the largest coverage figure here, and the VeSync app reports PM2.5 in real time with scheduling, fan-speed automation, and filter-life tracking, plus Alexa and Google Assistant support. The True HEPA plus activated carbon cartridge does verified submicron particle capture and odour control, and because it is a pure-HEPA design there are no ionising by-products to consider. The honest weaknesses: the combined HEPA-plus-carbon cartridge has to be swapped as one unit, so 24/7 use raises the annual filter cost; full smart features need a VeSync account; and there is no humidifying function for dry winter air.

▶ Video review

Levoit Core 400S - Top-Rated Smart Air Purifier Review (+ Smoke Test)