The 13 Best Amazon Air Purifiers — Starting at $40

Coway Airmega 100 True HEPA Air Purifier ($120, originally $130)

Unlike other air purifiers, the Airmega 100 has a 3-stage filtration system that captures 99.999-percent of nano-sized particles down to 0.01 microns (smaller than most allergens, bacteria, mold, and viruses). It also monitors the quality of the air, has a sleep mode, a night light, and a timer. What's more, it can clean spaces up to 405 square feet in 30 minutes or up to 810 square feet in 60 minutes.