Smart Home
Levoit Core 400S Review: The Critics’ Verdict

"It cleaned the air in my living room quickly and quietly." — Tom's Guide
No single aggregate score — here's what the reviewers agree on, below.
The short version
Critics agree that the Levoit Core 400S is an effective, approachable smart air purifier. Tom's Guide praised its quick, quiet cleaning and easy controls, while Engadget made it its best overall air purifier after it repeatedly cleared test-room pollution in about 30 minutes on high. CNET also recorded good cleaning performance, but found that the Blueair 311i Max performed better in a similar package. The Core 400S makes the strongest case below $200, especially if you value automatic operation and app control.
What reviewers loved
- Fast particle removal: CNET measured an average T90 of 1 minute and 49 seconds in its smoke-chamber testing.
- Responsive Auto mode: Engadget reports that it reliably increases fan speed after cooking or burning incense.
- Quiet low-speed operation: CNET ranked it as the third-quietest model at low fan settings, while Tom's Guide praised its quiet everyday cleaning.
- Clear, useful controls: the display shows a PM2.5 reading and uses a color-coded ring to make air quality easy to understand.
- Affordable filters relative to some rivals: Engadget says the $50 replacement costs half as much as filters from certain competing brands.
What held it back
- It is not the strongest performer in its price class: CNET says the Blueair 311i Max delivers better overall performance in a similar package.
- The value is less convincing around its $219 to $230 reviewed price; CNET recommends looking for a sale below $200.
- High-speed operation is noticeably louder: Tom's Guide calls Turbo mode rather loud, and Engadget lists a maximum of 64 decibels.
- Running costs add up because the $50 filter may need replacement as often as every six months, according to Tom's Guide.
Buy it if you want effective automatic air cleaning, understandable air-quality feedback and useful smart controls in a simple mid-sized unit.
Skip it if maximum particle-removal performance matters more than app features, or if it is priced above $200 beside a stronger rival.
What the reviewers say
Tom's Guide was impressed by how quickly and quietly the Core 400S cleaned a living room. It also praised the minimalist design, straightforward controls and portable 11-pound body. Its Airsight Plus sensor displays a PM2.5 reading and changes the surrounding LED ring according to detected air quality.
Engadget found that the purifier repeatedly returned its test room to its starting air-quality level in about 30 minutes on high. It also reports that Auto mode reacted reliably to cooking and incense. CNET's lab results support the broader positive verdict, with good overall cleaning performance and moderate noise and energy use, but CNET still preferred the Blueair 311i Max for outright performance.
⚙ Best settings — dial it in
There are no calibration numbers to enter. Engadget's testing supports using the built-in modes according to the room and activity. For fully calibrated values, see Engadget.
| Everyday use | Select Auto mode so the sensor can raise the fan speed when particulate levels increase. |
|---|---|
| Overnight | Use Sleep mode to run the fan at its lowest intensity and switch off the display lights. |
| After cooking or smoke | Run the purifier on High; Engadget's burn tests returned the room to its starting level in about 30 minutes. |
The competition
Blueair Blue Pure 311i Max
CNET says it offers better overall performance in a similar package, making it the stronger choice when cleaning speed takes priority.
Coway AP-1512 HH Mighty
Tom's Guide identifies it as a similarly capable alternative at roughly the same reviewed price.
Should you buy it?
Yes, with one pricing condition. The Levoit Core 400S combines good cleaning performance, quiet low-speed operation and genuinely useful automation. It is especially easy to live with because the sensor, color ring and Auto mode handle routine changes without much input. Its weakness is relative value: CNET found a better-performing rival and considers the Core 400S most appealing below $200. RightWei summarizes independent hands-on tests from professional reviewers and does not test review units itself.
Sources
RightWei aggregates and summarizes independent reviews — we link to the original hands-on tests so you can go deeper. We don't test units ourselves.