Allergies are the number-one reason people buy an air purifier, and the good news is the requirements are simple: a genuine True HEPA filter, enough clean-air output for your room, and filters cheap enough that you'll actually change them. Everything below meets that bar. The picks range from a $100 bedroom unit to a large-room machine, and each links to our full research-based review.
Quick answer
| Model | CADR (smoke) | Coverage | Filters/yr | Best for |
|---|---|---|---|---|
| Coway Airmega AP-1512HH Mighty | 233 CFM | 361 sq ft | ~$45 | Best overall |
| Levoit Core 300S | 141 CFM | 219 sq ft | ~$30 | Budget bedroom |
| Coway Airmega 400 | 328 CFM | ~780 sq ft | ~$80 | Large rooms |
| Winix 5510 | 253 CFM | 392 sq ft | ~$80 | Smart control |
| IQAir HealthPro Plus | — | 1,125 sq ft | ~$200 | Severe sensitivity |
IQAir rates its HyperHEPA media rather than publishing an AHAM CADR, so no smoke CADR is listed for it.
Key takeaways
- True HEPA (H13) is non-negotiable for allergies — it captures 99.97% of particles at 0.3 microns, including pollen, dust mite debris, and dander. Avoid "HEPA-type."
- Size by CADR, not by a vague coverage claim: aim for four to five air changes per hour in the room you'll use it in.
- The bedroom is the highest-value spot — clean air while you sleep does the most for morning symptoms.
Best overall for allergies: Coway Airmega AP-1512HH Mighty
Mid-range · 233 CFM CADR · 361 sq ft
The Mighty is the purifier we'd point most allergy sufferers to first. It pairs a real True HEPA and activated-carbon filter with a smoke CADR of 233 CFM — enough for a bedroom or a mid-size living room at a strong air-change rate — and it runs quietly on its lower speeds with a trustworthy auto mode that ramps up when its sensor detects a spike (like pollen tracked in on clothes). Filters are among the cheapest to replace, so you won't be tempted to stretch them past their life. The only things it lacks are an app and a reason to spend more.
Best budget for allergies: Levoit Core 300S
Budget · 141 CFM CADR · 219 sq ft
If you want real allergy relief in a bedroom for around $100, the Core 300S is the pick. It uses a genuine H13 True HEPA filter, has an air-quality sensor and auto mode, and drops to a near-silent sleep setting — ideal for overnight running, which is when allergy purifiers earn their keep. It's sized for small rooms, so don't ask it to handle a great room, but within its footprint nothing beats it for the money.
Best for large rooms: Coway Airmega 400
Premium · 328 CFM CADR · 1560 sq ft
For an open-plan living space or a large bedroom, the Airmega 400 brings a much higher CADR — around 350 CFM — feeding two full True HEPA and carbon filters, with the same quiet, sensor-driven auto mode as its smaller sibling. It's a step up in price and size, but if your problem room is big, a properly sized machine is the difference between "helps a little" and "the sneezing stops."
Best smart pick: Winix 5510
Mid-range · 253 CFM CADR · 392 sq ft
If you want app control and scheduling on top of solid allergy performance, the 5510 delivers True HEPA plus carbon, coverage up to roughly 392 sq ft, and Wi-Fi with an auto mode you can manage from your phone. It's the pick for someone who wants to set a schedule — ramp it up before pollen season mornings — without stepping up to premium money.
Best for severe allergies and sensitivities: IQAir HealthPro Plus
Luxury · 1125 sq ft
When allergies shade into genuine sensitivity — or you simply want the strongest filtration available — the HealthPro Plus is the benchmark. Its HyperHEPA filter is rated to capture particles well below the standard HEPA threshold, and a large gas-and-odor stage handles the VOCs that some people react to as well. It's expensive to buy and to re-filter, and the base model has no app, but for sheer filtration quality in a large room it sets the bar.
How to choose the right one for you
Start with the room. Measure it, then use the room-size to CADR calculator to get a target — you want a smoke CADR of at least two-thirds of the room's square footage, more if you can. Then pick the unit on this list that meets it within your budget. If money's tight, our best budget air purifiers roundup goes deeper on the value end. And if you're unsure whether a filter is genuine HEPA, read what a HEPA filter really is before you buy — "HEPA-type" is not the same thing.
Frequently asked questions
Do air purifiers help with allergies?
Yes. A True HEPA purifier sized correctly for the room measurably lowers airborne allergens — pollen, dust mite debris, pet dander, and mold spores. It won't touch allergens that have settled into carpet or bedding, so pair it with regular cleaning, but for the airborne fraction the effect is real and well documented.
What should I look for in an air purifier for allergies?
Three things: a genuine True HEPA (H13) filter, a CADR high enough for your room (aim for four to five air changes per hour), and an affordable filter you'll actually replace on schedule. Skip ionizer-only or 'HEPA-type' units.
Do I need a special allergy air purifier?
No — any well-sized True HEPA purifier is an allergy purifier, because HEPA is what captures the fine particles allergies react to. What matters is matching the CADR to your room, not a marketing label.
Where should I run an air purifier for allergies?
The bedroom first. You spend a third of your day there, and overnight is when running clean air does the most good. If you can only afford one unit, put it where you sleep.
How long does it take an air purifier to help with allergy symptoms?
Give it time and steady running. A well-sized purifier can lower airborne allergens within an hour or two, but noticeable symptom relief usually builds over days of continuous use as the standing load of pollen and dander in the room drops. Run it 24/7 on auto rather than in short bursts, and keep windows closed during high-pollen periods.