Humidifier 311 4L vs Dreo Smart Humidifier
Both are Dreo 4L ultrasonic cool-mist humidifiers rated for 300 sq ft, 28 dB and 36 hours of runtime, so the real split is price and control. The Humidifier 311 is $39.99 at Amazon as of November 3, 2026, and the Smart Humidifier is $29.99 at eBay as of the same date. Buy the Smart Humidifier for the lower price and the same core specs; buy the 311 only if you want its higher rating volume and the specific HM311 model.
Today the Humidifier 311 4L costs $10.00 less at its best price.
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Humidifier 311 4L
4.7Choose the Humidifier 311 if you want the model with 310 ratings behind it and a proven 4.7 score, and the $10 gap does not matter to you.
- 310 ratings at 4.7 out of 5 give a much larger track record than 17 ratings.
- Top-fill tank and modular parts make cleaning easy.
- 28 dB sleep mode and auto humidistat suit bedrooms.
- Aroma pad included for essential oils.
What separates them
| Humidifier 311 4L | Dreo Smart Humidifier | |
|---|---|---|
| Price (new) | $39.99 at Amazon as of November 3, 2026 | $29.99 at eBay as of November 3, 2026 |
| Rating volume | 4.7 out of 5 from 310 ratings | 4.9 out of 5 from 17 ratings |
| Tank and runtime | 4L, up to 36 hours (listing also says 32) | 4L, up to 36 hours |
| Noise | 28 dB | 28 dB |
| Coverage | 300 sq ft | 300 sq ft |
| Mist | Ultrasonic cool mist, 5 µm particles, 40 in mist height | Ultrasonic cool mist, 5 µm particles |
| Controls | App, voice assistant, touch, auto/sleep/manual modes, timer | App, touch, Alexa or Google Assistant, auto mode, timer, ambient light |
| Stores stocking it new |
Price history
- Humidifier 311 4L: lowest $39.99 on Nov 4 at Amazon.
- Dreo Smart Humidifier: lowest $49.99 on Nov 4 at DREO.
Prices at every store
Humidifier 311 4L
- DREONew
In stockReturn policy
$39.99Verified - AmazonNew
Availability unknown
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$39.99Free shippingObserved at 8:25 PM
Also available at
Dreo Smart Humidifier
- DREONew
In stock
$49.99Free shippingObserved at 8:25 PM - Babe LullabyNew
In stockReturn policy
$79.99Observed at 10:00 PM - PetalPath GardenNew
In stockReturn policy
$83.98Observed at 10:00 PM - AmazonNew
Availability unknown
As an Amazon Associate, Deal.ai earns from qualifying purchases.
$49.99Free shippingObserved at 8:25 PM
Also available at
- KiddoCoveCheck price at KiddoCove
- DwellinhausCheck price at Dwellinhaus
- LittleSprout BoutiqueCheck price at LittleSprout Boutique
Specs compared
| Spec | Humidifier 311 4L | Dreo Smart Humidifier |
|---|---|---|
| Coverage Area | 300 ft² | 300 sq ft coverage |
| Water Tank Capacity | 5 L | 4L |
| Depth | 10.71 in | 5.51 in deep |
| Noise Level | 28 dB | 28 dB |
| Runtime | 36H | 36 H |
| Colour | White | Black |
| Humidification Type | Ultrasonic | — |
| Volume | 5 L | — |
| Automatic Shutoff | Yes (stops when desired humidity is reached) | — |
| Timer | Yes (scheduling via app) | — |
What reviewers say
Humidifier 311 4L
Rated 4.7 out of 5 from 310 ratings. Owners mostly praise how quiet it is, how easy it is to fill and clean, and how it helps with dry mouth and congestion. Complaints center on runtime falling short of the claim, early failures, and the lack of separate replacement tanks.
- Silent enough for night use
- Easy top-fill and easy cleaning
- Helps with dry mouth, coughs and congestion
- Mist does not pool on furniture
- Runs closer to 24 hours than 32, and under 12 for one owner
- One unit stopped working after about 3 months
- One unit arrived with a crack
- Replacement tanks not sold separately
Dreo Smart Humidifier
Owners rate it highly, at 4.9 out of 5 from 17 ratings, and most praise quiet operation, easy top-fill refills and steady auto-mode humidity. Complaints are few and center on app setup and the small coverage for larger rooms.
Questions and answers
- Which is better for a bedroom?
- Both run at 28 dB with a 4L tank and 36-hour runtime, so either works. The 311 has far more owner reviews, while the Smart Humidifier adds voice control and costs less.
- Is the Humidifier 311 worth $10 more?
- Only if you value its 310-rating track record over the Smart Humidifier's 17 ratings. The specs are otherwise nearly identical, so the cheaper unit is the better value on paper.
- Do both need distilled water?
- Yes. Both are ultrasonic, which throws minerals into the air as white dust. Use distilled or filtered water and descale the tank regularly.
- Which covers a larger room?
- Neither. Both are rated for 300 sq ft, which is a medium bedroom or living area, not a whole house.
- Which has better smart controls?
- The Smart Humidifier lists app, touch, Alexa and Google Assistant plus ambient light. The 311 lists app and assistant support with auto, sleep and manual modes.
- How long do they run on a fill?
- Both claim up to 36 hours on the 4L tank, though the 311's own listing also says 32 hours and some owners report closer to 24 in very dry air.
