Levoit · Shows PM2.5
Levoit Core 400S
A mid-size smart purifier that shows the room's PM2.5 on its display, adjusts itself in auto mode and runs from Levoit's VeSync app.
- Laser PM2.5 sensor with a live readout
- App, Alexa and Google control
$189.99at levoit.com · sale price, was $219.99 · Nov 2026
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- smoke CADR: clean air it moves each minute
- 231 cfm
- room size it suits, every day
- 33 m²
- 358 ft²
- room size on smoggy days
- 21 m²
- 231 ft²
Levoit Core 400S at a glance
- Smoke CADR
- 231 cfm (Energy Star listing)
- Filter
- Pre-filter, HEPA and activated carbon
- Replacement filter
- Core 400S-RF (pet, smoke and toxin versions too)
- Sensor
- Laser particle sensor; PM2.5 shown on the display
- Smart features
- VeSync app, Alexa, Google Assistant, auto mode
- Ioniser
- None: Levoit says it makes no ions or ozone
Which rooms it suits
Everyday: AHAM's room size. Smog: AHAM's advice for smoke, a CADR at least equal to the floor area in ft².
| Room | Everyday | Smog days |
|---|---|---|
| Bedroom · 15 m² (161 ft²) | ||
| Living room · 30 m² (323 ft²) | ||
| Large room · 50 m² (538 ft²) |
Our take
The 400S puts a number on the air. Its laser sensor shows the room's PM2.5 on the front, and in auto mode the fan follows it: up when someone cooks or the smog seeps in, down when the room is clean.
With a smoke CADR of 231 cfm it suits rooms of about 33 m², a bedroom or a modest living room. There is no ioniser to switch off, which keeps it simple.
What's good
- Live PM2.5 number on the unit
- No ionizer: Levoit says it makes no ions or ozone
- App, Alexa and Google
What's not
- Its filter costs more than the Core 300's
- Not enough for a big open-plan room
Its filter: Levoit Core 400S Replacement Filter · $49.99 at levoit.com
Good for
- Bedrooms and living rooms up to about 33 m²
- Seeing the PM2.5 in the room without buying a separate monitor
Skip it if
- You want nothing to do with apps: it works with buttons, but its best features live in VeSync
How it compares
Every air purifier in the shop.
| Product | Best for | Smoke CADR | Room size | Price |
|---|---|---|---|---|
| Levoit Core 300S | Smart bedroom | 141 cfm | 20 m² | $149.99 |
| Levoit Core 300 | Budget bedroom | 143 cfm | 21 m² | $89.99 |
| Levoit Vital 100S | Pet-friendly bedroom | 143 cfm | 21 m² | $119.99 |
| Coway Airmega 150 | Small & quiet | 153 cfm | 22 m² | $189.99 |
| Levoit Core 400S (this one) | Shows PM2.5 | 231 cfm | 33 m² | $189.99 |
| Winix C545 | Everyday pick | 232 cfm | 33 m² | $209.99 |
| Coway Airmega AP-1512HH Mighty | Best overall | 233 cfm | 34 m² | $239.99 |
| Coway Airmega AP-1512HHS (Mighty with Wi-Fi) | Smart Mighty | 233 cfm | 34 m² | $299.99 |
| Coway Airmega 200M | Mighty's twin | 233 cfm | 34 m² | $229.99 |
| Levoit Vital 200S | Pet homes | 250 cfm | 36 m² | $169.99 |
| Honeywell HPA300 | No-frills power | 300 cfm | 43 m² | $269.95 |
| Coway Airmega 400 | Big rooms | 376 cfm | 54 m² | $649.00 |
| Levoit Core 600S | Large rooms | 391 cfm | 56 m² | $299.99 |
| Blueair Blue Pure 211i Max | Most clean air | 435 cfm | 63 m² | $349.99 |
| Filtrete MPR 1900 MERV 13 filters for a DIY box-fan purifier (4-pack) | Budget build | — | — | $87.99 |
Its filter, and related models
Levoit Core 400S-RF Original FilterCore 400S · $49.99
In our buying guides
Head to head
Questions about the Core 400S
- What size room does the Levoit Core 400S cover?
- About 358 ft² (33 m²). That's AHAM's room size for its smoke CADR of 231 cfm: the floor area, with an 8 ft ceiling, whose air it cleans about every 12.5 minutes.
- Is the Levoit Core 400S enough for smog?
- For smoke and heavy smog AHAM suggests a smoke CADR at least equal to the floor area in square feet. By that measure the Levoit Core 400S keeps up with a room of about 231 ft² (21 m²). Keep the windows shut and run it on high while the AQI is bad.
- Does the Levoit Core 400S have an ioniser?
- No. Levoit says it's ozone-free and makes no ions. The similarly named PlasmaPro 400S is the model with an ioniser.
- How accurate is its PM2.5 reading?
- Like every built-in sensor it's best at showing change: up when the air gets worse, down as the purifier works. For exact figures, use a dedicated monitor.
How we judge. We haven't tested the Core 400S in a lab of our own. The figures come from independent ratings (AHAM, Energy Star, NIOSH, the ASPCA) or the maker, and the verdict is ours, from those figures. No brand pays to be listed. Last checked Nov 7, 2026.
Levoit Core 400S
$189.99 list price