Best air purifiers

Top pick: Levoit Core 400S. It's the best all-rounder here — real HEPA filtration with a PM2.5 sensor and auto mode, so it speeds up on its own when dust or smoke rises, and it covers a normal living room or bedroom without being huge or loud.

Who the others suit:

• Winix Zero — the biggest, most thorough unit here (4-stage H13 HEPA, very high CADR); pick it for a large open-plan space or serious allergy sufferers.
• Coway Airmega 400(G) — whole-floor coverage and smart features; the choice for a big home if you want one machine to do it all.
• Medify MA-40 — a solid mid-size HEPA unit for a bedroom or office; simple, three speeds, no smart extras.
• Levoit Core 300-P / MA-14 — compact, affordable bedroom purifiers for allergens.
• Honeywell HPA030 — a plain, dependable tower with no app fuss.
• Levoit Core Mini-P / DREO / ALROCKET — small deskside or nursery units; fine for a single small room, not a whole home.

Check the filter replacement cost and noise on the highest setting before you commit — those matter more day to day than the spec sheet.