Best Air-Purifying Houseplants
The houseplants made famous by NASA's clean-air study, what the research actually shows about indoor air, and how to use these plants realistically.
In 1989, a NASA study tested whether common houseplants could remove airborne toxins like formaldehyde, benzene, and trichloroethylene from sealed chambers, and the answer was yes. That study launched the entire 'air-purifying plant' category and the species below are its all-stars. They're genuinely effective at absorbing certain compounds, and they're also simply great, easy houseplants worth owning regardless.
Honesty matters here. The NASA tests used small, sealed chambers, and later research found that to meaningfully clean the air of a normal room you'd need a dozen or more plants per 100 square feet, far more than most homes have. A single plant won't measurably purify your living room. Grow these because they're beautiful, forgiving, and add life to a space, and treat any air-quality benefit as a small bonus on top.
The NASA study's top performers
Several plants stood out in the original research for removing multiple compounds. The peace lily ranked among the best overall, absorbing formaldehyde, benzene, and trichloroethylene while also being an easy, low-light bloomer. The areca palm and other palms scored well and add tropical presence. English ivy is effective and trails attractively, though it's toxic to pets. The snake plant and golden pothos both performed strongly and are nearly indestructible, making them the most practical picks.
These species combine real lab performance with easy care, which is why they appear on every air-purifying list. You can't go wrong choosing among them for a tough, attractive plant.
More clean-air all-stars
The spider plant removes formaldehyde and is one of the safest, easiest plants you can grow, plus it's pet-safe. Dracaenas, including the corn plant and dragon tree, were strong performers and make handsome upright accents. The rubber plant and Boston fern also featured in the research, the fern being especially good at humidifying as well. The chrysanthemum and gerbera daisy topped some charts but are short-lived indoors, so the foliage plants are more practical for a permanent collection.
Notably, almost every plant on this list is also forgiving and widely available. That overlap is no accident: the easy, leafy tropicals that survive indoor conditions are the same ones that process airborne compounds in lab settings.
How to actually improve your indoor air
If your real goal is cleaner air, the most effective steps are mechanical: open windows for cross-ventilation, run an exhaust fan, and use a HEPA air purifier sized for the room, which moves vastly more air than any number of plants. Reducing sources, low-VOC paints, fragrance-free products, and good ventilation when cooking or cleaning, does more than filtration of any kind.
Plants still contribute in small ways: they add humidity, soil microbes process some compounds, and caring for greenery measurably lowers stress. So pair a few of these plants with good ventilation and a purifier rather than relying on the plants alone, and you get both the small biological benefit and the genuine psychological one.
- Don't rely on plants alone for air quality; a HEPA purifier and open windows do far more
- More leaf surface means more processing, so larger, leafier plants edge out small ones
- Keep leaves dust-free; clean leaves exchange gases and absorb compounds more efficiently
- Several top performers like ivy and peace lily are toxic to pets, so choose accordingly
FAQ
How many plants do I need to purify a room's air?
Far more than is practical. Research building on the NASA study estimates you'd need roughly 10 or more large plants per 100 square feet to make a measurable dent in a normal, ventilated room, since real rooms exchange air constantly while the NASA chambers were sealed. A handful of plants won't noticeably clean your air. For real air quality, rely on ventilation and a HEPA purifier, and enjoy the plants for their other benefits.
Is the NASA clean-air study still valid?
The study itself was real and well-conducted, but it tested plants in small sealed chambers, not living rooms. Its findings have been widely overstated by marketers. Plants do absorb some airborne compounds, and that part holds up, but the effect in a ventilated home is small. Treat the famous list as a guide to easy, attractive plants rather than as proof they'll purify your house.
Which air-purifying plant is easiest to care for?
The snake plant, golden pothos, and spider plant are the easiest of the clean-air all-stars. All three tolerate low light, irregular watering, and general neglect, and the spider plant has the bonus of being pet-safe. The peace lily is also very easy and conveniently wilts to tell you when it's thirsty. Any of these gives you the small air benefit plus a genuinely low-maintenance plant.