Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Blueair - 7770i | Coway - Airmega 400 |
|---|---|---|
| Coverage | 100 m² | 60 m² |
| CADR | 900 m³/h | 705 m³/h |
Between the 7770i and Airmega 400, the 7770i comes out ahead in coverage / cadr, while the Airmega 400 wins on several specs. Overall, the 7770i scores 93.1 and the Airmega 400 scores 85.4 on our Mars Score.
Which should you buy?
The 7770i edges ahead on the Mars Score (93.1 vs 85.4), but the 7.7-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the 7770i if you care most about coverage / cadr. The biggest gaps in its favor are coverage, cadr. The single most decisive one: Coverage — 66.67% more. 100 m² vs 60 m².
The Airmega 400 similarly does not carry a headline advantage on the popular specs — look at the full table for category-specific deltas.
Both ship with comparable true hepa h13+, activated carbon, min noise, so those specs do not separate the two — focus on the differences below.
Bottom line: the 7770i is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Which should you buy: Blueair - 7770i or Coway - Airmega 400?
Blueair - 7770i leads the current Mars Score by 7.7 points.The more useful decision is the trade-off behind that result: compare cadr, coverage against the way you will actually use the product.
Choose Blueair - 7770i if…
Blueair - 7770i has the measurable edge on coverage m2, cadr m3h.
Choose Coway - Airmega 400 if…
Coway - Airmega 400 does not lead a decisive measured field here, so choose it for price, ecosystem, design, or availability when those matter more to you.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Blueair - 7770i wins
- ▲Coverage — 66.67% more. 100 m² vs 60 m².
- ▲CADR — 27.66% more. 900 m³/h vs 705 m³/h.
Why Coway - Airmega 400 wins
- No decisive advantages.
Spec comparison
Performance
| Spec | Blueair - 7770i | Coway - Airmega 400 |
|---|---|---|
| CADR | 900 m³/hlead | 705 m³/h |
| Coverage | 100 m²lead | 60 m² |
| True HEPA H13+ | true | true |
| Activated carbon | true | true |
Smart & Noise
| Spec | Blueair - 7770i | Coway - Airmega 400 |
|---|---|---|
| Min noise | 22 dB | 22 dB |
| Air quality sensor | true | true |
| Smart app | true | true |