Air purifiers
Portable filters that take fine particles out of indoor air without adding anything to it.
How we rank air purifiers
- Filtration 30%
- Adds nothing to the air 20%
- Independent testing 20%
- Trust 10%
- Running cost & value 20%
Why, and what each one means
Purifiers reliably cut indoor particles, and a 2023 meta-analysis (opens in a new tab) found a small drop in blood pressure; asthma results are mixed (see our review). So we score how much clean air a machine delivers, by measured CADR and not coverage claims (how to size one), then whether it adds anything to the air, who tested it and who paid, what it costs to run and how its maker behaves.
- Filtration 30%
- True HEPA (or H13) and a smoke CADR from AHAM’s directory or a named lab that fits the room. Coverage claims with no certified CADR score low.
- Adds nothing to the air 20%
- Mechanical filtration only, on CARB’s list as a mechanical cleaner: no ionizer, plasma, UV or photocatalytic stage, and no scent.
- Independent testing 20%
- Highest when someone the maker does not pay (a consumer group, journalist, university or regulator) has tested it for the contaminants that matter here and published clean results. A certification the maker pays for, or the maker’s own lab reports, count for less, and claims with nothing published count for little.
- Trust 10%
- Highest when the maker names everything, answers questions, and has no recalls, warning letters, Prop 65 notices or lawsuits over safety or labeling. Points come off for unresolved problems and for paid promoters it does not disclose.
- Running cost & value 20%
- Purchase price, filter price and change interval, and power use, against purifiers of a similar CADR.
Each product scores every one from 1 to 5, and its rating is the weighted average. We list only products rated 3 or above that break none of our rules.
We avoid
- Ionizers, “plasma”, hydroxyl and other ozone-producing “air sanitizers”.
- “HEPA-type”, “HEPA-like” or “HEPA-style” wording, which has no defined meaning.
- Coverage claims counted over 30 minutes, or at one air change an hour, instead of a certified CADR.
- Units whose replacement filters you cannot price before you buy.
Read the research
Know one that fits? Suggest a product
9 products · best rated first
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CowayCoway Airmega Mighty2 Air Purifier (AP-1512N)
The successor to the popular Mighty: filter-only, listed by CARB as mechanical, with its ionizer gone. RTINGS and HouseFresh measured its CADR within 10% of Coway’s 240. Its HEPA test is Coway’s own, and AHAM has no Coway entry. Listed by CARB as a mechanical air cleaner (AP-1512N) -
LevoitLevoit Eleva 300X Air Purifier
A budget, filter-only purifier: CARB lists it as mechanical, AHAM at a smoke CADR of 161, and HouseFresh measured 165 cfm. The HEPA lab is unnamed, and Levoit’s maker is settling a HEPA-wording lawsuit over older models. Listed by CARB as a mechanical air cleaner (LAP-C341S-WUSZ) · AHAM Verifide CADR listing (smoke 161) -
LevoitLevoit Eleva 500X Air Purifier
A filter-only purifier with an AHAM smoke CADR of 301 and a CARB mechanical listing, at about $0.86 per CFM. We found no independent test of it yet, its HEPA lab is unnamed, and its maker is settling a HEPA-wording lawsuit. Listed by CARB as a mechanical air cleaner (LAP-C511S-WUS) · AHAM Verifide CADR listing (smoke 301) -
CowayCoway Airmega 400 Air Purifier (AP-2015F)
A large-room, filter-only purifier. CARB lists it as mechanical and ENERGY STAR shows a smoke CADR of 376, above Coway’s own 328. Filters run $129 a year. No AHAM listing or app, and its 3,120 sq ft headline counts one air change an hour. Listed by CARB as a mechanical air cleaner (AP-2015F) · ENERGY STAR certified room air cleaner (AP-2015F); its list shows a smoke CADR of 376 and 0.00 ppb ozone -
OransiOransi AirMend 270HB Air Purifier
A HEPA-only purifier assembled in Virginia. CARB lists it as mechanical and AHAM gives it a smoke CADR of 237; reviewers tested its smaller siblings. It has no carbon, is loud on high, and Oransi’s HEPA lab is unnamed. Listed by CARB as a mechanical air cleaner (AMD-270HB) · AHAM Verifide CADR listing (smoke 237) -
OransiOransi Mod+ Air Purifier
A HEPA and carbon purifier for large rooms, with an AHAM smoke CADR of 363 and a CARB mechanical listing. It costs about twice the Levoit Eleva 500X per unit of clean air, and its HEPA, formaldehyde and nanoparticle tests are Oransi’s own. Listed by CARB as a mechanical air cleaner (MD02) · AHAM Verifide CADR listing (smoke 363) -
Austin AirAustin Air HealthMate (B400)
A US-built steel purifier with a very large carbon, zeolite and HEPA filter rated for five years, and an NIH-funded asthma trial. It publishes no CADR; HouseFresh measured about 160 cfm, far below its 1,500 sq ft claim. About $845. Listed by CARB as a mechanical air cleaner (HealthMate HEPA Plus, HM400) -
DysonDyson Purifier Big+Quiet Formaldehyde BP04
Dyson’s largest purifier: CARB lists it as mechanical, RTINGS measured 193 cfm at 33 to 48 dBA, and Dyson calls it fully sealed. It gives no CADR or lab reports. About $900 on sale, $1,199.99 list. We have asked Dyson for the reports. Listed by CARB as a mechanical air cleaner (BP04 YY and BP04 ZZ) -
IQAirIQAir HealthPro Plus XE Air Purifier
A Swiss-made HEPA and carbon purifier that CARB lists as mechanical, with filter prices and noise by speed published. IQAir rejects CADR and gives no certified room rating; HouseFresh measured the older model at about 213 cfm. About $1,200. Listed by CARB as a mechanical air cleaner (HealthPro Plus XE)