Choose either model after comparing CADR, recommended room size, noise, and filtration below.
Which purifier has higher CADR?
The Blueair Blue Signature has a smoke CADR of 455 CFM versus 435 CFM for the Blueair Blue Pure 211i Max, a difference of 5%.
Which purifier is quieter?
Both list a minimum of 23 dB.
Which purifier covers a larger room?
Blueair Blue Signature fits a larger room (about 705 vs 674 sq ft recommended from CADR).
Which purifier has better smart features?
Both list smart features (7 stages of filtration, 10x more odor removal, Smart VOC sensor, Dynamic display vs Captures 99.97% of particles as small as 0.1 microns, RealTrack technology for filter lifetime tracking, WiFi connectivity with smart features).
Which purifier has better filtration?
Both list HEPASilent filtration.
Bottom line
Choose either model after comparing CADR, recommended room size, noise, and filtration below.
| Metric | Blueair Blue Signature | Blueair Blue Pure 211i Max | Difference / Winner |
|---|---|---|---|
| Smoke CADR | 455 CFM | 435 CFM | Blueair Blue Signature (+5%) |
| Recommended room size | 705 sq ft | 674 sq ft | Blueair Blue Signature (+5%) |
| Manufacturer claimed coverage | 3385 sq ft | 3235 sq ft | — |
| Minimum noise | 23 dB | 23 dB | — |
| Filter type | HEPASilent | HEPASilent | — |
| Power | 42 W | 46 W | — |
| Wi-Fi / app | Yes | Yes | — |
| Dimensions | 17.2 × 15.5 × 15.5 in | 22.7 × 14.4 × 14.4 in | — |
| Weight | 13.2 lb | 16.2 lb | — |