Air purifiers, coffee makers, robot vacuums, fans — the appliances you notice only when they stop working.
Home appliances are the category where the purchase price is the least interesting number. We look hardest at what a thing costs to keep running — filters, pods, descaling, replacement brushes — and at whether it is still serviceable in three years. A cheap purifier with an expensive proprietary filter is not a cheap purifier. Noise matters more than most spec sheets admit, so we favour picks where somebody has actually measured it.
22 roundups here so far. Every one lists the reviews and testing it was built from — we don't test products ourselves. How we pick.