Coway Airmega 400 vs Blueair Blue Pure 311i+ — Which Should You Buy?
Side-by-side comparison of Coway Airmega 400 and Blueair Blue Pure 311i+. We compare specs, performance, and value to help you decide.
Feature Comparison
| Feature | Coway Airmega 400 | Blueair Blue Pure 311i+ |
|---|---|---|
| Room Coverage | Up to 1,560 sq ft | Up to 387 sq ft |
| CADR | 361 (smoke), 377 (dust), 403 (pollen) | 250 (smoke), 250 (dust), 250 (pollen) |
| Filter Type | Green True HEPA + activated carbon | HEPASilent + activated carbon |
| Filter Life | 12 months | 6 months (main filter) |
| Annual Filter Cost | ~$70 | ~$60 |
| Noise Level | 24–52 dB | 31–56 dB |
| Smart Features | None | App, scheduling |
| Air Quality Sensor | Yes (particle indicator) | Yes |
| Weight | 18.7 lbs | 8.4 lbs |
| Energy Star | Yes | Yes |
Coway Airmega 400
Pros
- ✓Covers up to 1,560 sq ft
- ✓Dual filtration with Green True HEPA
- ✓Filter replacement indicator
- ✓Energy-efficient operation
- ✓Quiet on low and medium settings
- ✓Sleek, compact design
- ✓5-year warranty
Cons
- ✗No smart connectivity
- ✗Filter costs add up over time
- ✗Heavier than some competitors
Blueair Blue Pure 311i+
Pros
- ✓HEPASilent technology is very quiet
- ✓Washable fabric pre-filter
- ✓Energy-efficient operation
- ✓App control and scheduling
- ✓Multiple filter color options
- ✓Compact design
- ✓Low filter costs
Cons
- ✗Lower CADR than competitors
- ✗Fabric filter attracts dust visibly
- ✗No particle display
Our Verdict
Coway Airmega 400
Our top value pick for large rooms. Outstanding CADR, reliable filtration, and solid build at a price that undercuts premium competitors.
Price Drop Alert — View Deal NowBlueair Blue Pure 311i+
A solid choice for smaller rooms where quiet operation and aesthetics matter. The washable pre-filter helps reduce long-term costs.
Limited Offer — Check Today's PriceOur Methodology
We test each air purifier in a sealed 250 sq ft room with a particle counter, measuring PM2.5 reduction over 1 hour. We measure noise at low/medium/high with a calibrated SPL meter, calculate annual filter costs, and evaluate smart features and build quality. No manufacturer has editorial influence.
Related Comparisons
Best Air Purifiers 2026
Our tested rankings of the best air purifiers for 2026. Compare CADR, room coverage, filter costs, and smart features. No manufacturer influence.
OverviewCompare Air Purifiers
Compare air purifiers side by side. CADR, HEPA type, room coverage, and filter costs. Find the right purifier for your space.
CompareCompare PurifierPick Products — Pick Two to Compare
Choose any two products to see a detailed side-by-side comparison. Compare specs, features, and value.
Head to HeadDyson Big+Quiet vs Coway Airmega 400
Head-to-head comparison of Dyson Big+Quiet and Coway Airmega 400. Filtration, noise, smart features, and value compared.
Head to HeadDyson Purifier Big+Quiet Formaldehyde vs Blueair Blue Pure 311i+ — Which Should You Buy?
Side-by-side comparison of Dyson Purifier Big+Quiet Formaldehyde and Blueair Blue Pure 311i+. We compare specs, performance, and value to help you decide.
Head to HeadCoway Airmega 400 vs Levoit Core 400S — Which Should You Buy?
Side-by-side comparison of Coway Airmega 400 and Levoit Core 400S. We compare specs, performance, and value to help you decide.
Head to HeadCoway Airmega 400 vs Winix 5500-2 — Which Should You Buy?
Side-by-side comparison of Coway Airmega 400 and Winix 5500-2. We compare specs, performance, and value to help you decide.