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Dreo Smart Humidifier HM306S 3L Review | 43 Data compared

Avg. price in UK: ~£45
Avg. price in US: ~$50
Humidification rate: 250 ml/h
Maximum room area: 27.87 m²
Water tank capacity: 3 L
Maximum operating time: 30 hours
Maximum noise level: 30 dB

Dreo Smart Humidifier HM306S 3L review. Compare 43 technical specifications and user reviews to see how this product ranks in the Humidifiers category and whether it is worth buying.

7.9

Very good

7.6

Very good

9.2

Exceptional

8.5
Bedroom use
Score components:
35.0%
8.5
Maximum noise level
25.0%
6.0
Maximum operating time
20.0%
10
Timer
20.0%
10
Automatic low-water shut-off
5.8
Large rooms
Score components:
35.0%
6.1
Humidification rate
30.0%
4.4
Maximum room area
25.0%
5.3
Water tank capacity
10.0%
10
Hygrostat
7.9
Plant care
Score components:
30.0%
10
Hygrostat
25.0%
6.1
Humidification rate
25.0%
5.3
Water tank capacity
20.0%
10
360° nozzle

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Verdict

The Dreo Smart Humidifier HM306S is a 3-liter ultrasonic cool mist device designed for spaces up to 300 square feet, featuring a 2.4MHz high-frequency atomizer that releases a 5μm ultra-fine mist up to 40 inches high at a rate of 250ml/hr. Key advantages include an extensive 30-hour maximum runtime, ultra-quiet 26dB operation in sleep mode, a convenient top-fill design, an aroma pad tray for essential oils, customizable RGB ambient lighting, and intelligent auto-adjustments via a precision humidistat and app or voice control. However, notable drawbacks include a lack of built-in Wi-Fi memory that forces the unit to re-sync with the app when moved between rooms, and it does not offer a warm mist option.

Technical Specifications of humidifier Dreo Smart Humidifier HM306S 3L

Overall score

7.9

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Popularity

What it is: An indicator based on the number of reviews received by products in the Humidifiers category.

When it matters: When you prefer products in the Humidifiers category that have been chosen and reviewed by many other buyers.

Performance

6.9

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Technology

What it is: The method the humidifier uses to turn water into moisture for the room.

When it matters: Technology affects mist temperature, visible output, maintenance needs, and sensitivity to minerals in the water.

Importance: LOW

ultrasonic

Humidification rate

What it is: The maximum amount of water the humidifier can release into the air per hour.

When it matters: A higher rate raises room humidity faster and is more useful in dry or larger spaces.

Importance: HIGH

Good value: At least 300 ml/h

Maximum room area

What it is: The largest room floor area the humidifier is recommended to cover.

When it matters: A larger coverage rating is important for open-plan spaces and larger bedrooms or living rooms.

Importance: HIGH

Good value: At least 40 m²

Water tank capacity

What it is: The usable amount of water the humidifier’s reservoir can hold.

When it matters: A larger tank generally needs fewer refills and can support longer operation between top-ups.

Importance: HIGH

Good value: At least 4 L

Maximum operating time

What it is: The longest stated operating time from one full water tank.

When it matters: Longer runtime means fewer refills during overnight use or extended daily operation.

Importance: HIGH

Good value: At least 24 hours

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Features

8.4

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Warm mist function

What it is: Indicates whether the humidifier can produce warm mist as well as cool mist.

When it matters: Useful when you want warmer output in cool weather instead of cool mist alone.

Importance: HIGH

Good value: yes

Aromatherapy support

What it is: Indicates whether the humidifier supports the safe use of aromatic oils or fragrance media.

When it matters: Useful if you want to add fragrance without putting oil directly into the water tank.

Importance: MEDIUM

Good value: yes

Dedicated aroma compartment

What it is: Indicates whether the humidifier has a separate compartment for aroma pads or essential oils.

When it matters: A dedicated compartment keeps fragrance media separate from the main water tank.

Importance: LOW

Good value: yes

Automatic low-water shut-off

What it is: Indicates whether the humidifier switches itself off when the water level becomes too low.

When it matters: This safety feature helps prevent the unit from continuing to run with an empty tank.

Importance: HIGH

Good value: yes

Water level indicator

What it is: Indicates whether the humidifier shows the amount of water remaining in its tank.

When it matters: A visible level indicator makes it easier to know when the tank needs refilling.

Importance: MEDIUM

Good value: yes

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Design

7.4

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Fill type

What it is: The design mechanism used to add water to the humidifier tank, distinguished primarily between convenient top-fill and inverted bottom-fill designs.

When it matters: Top-fill humidifiers let you pour water directly into the top with a pitcher without carrying a heavy, dripping tank to the tap.

Importance: LOW

top fill

Color

What it is: The primary exterior color of the humidifier.

When it matters: Color matters when you want the humidifier to blend with the room.

Importance: LOW

white

Material

What it is: The primary material used for the humidifier’s exterior housing.

When it matters: Material matters for durability, feel and appearance.

Importance: LOW

plastic

360° nozzle

What it is: Whether the humidifier has a nozzle that rotates through 360° to direct the mist.

When it matters: A rotating nozzle helps redirect mist without moving the humidifier.

Importance: LOW

Good value: yes

Display

What it is: Whether the humidifier has a display for settings and status information.

When it matters: A display makes humidity, mode and timer information easier to check.

Importance: LOW

Good value: yes

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Dreo Smart Humidifier HM306S 3L vs the average humidifier

Why is Dreo Smart Humidifier HM306S 3L better than the average humidifier?

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Wi-Fi control
Dreo Smart Humidifier HM306S 3L supports Wi-Fi control; the average humidifier does not support Wi-Fi control.
What it is: Indicates whether the humidifier connects to Wi-Fi for remote app-based features.
When it matters: Wi-Fi matters if you want to adjust settings or monitor the humidifier away from its controls.
Importance: HIGH
Good value: yes
Dreo Smart Humidifier HM306S 3L supports Wi-Fi control; the average humidifier does not support Wi-Fi control.
Voice control supported
Dreo Smart Humidifier HM306S 3L supports voice control; the average humidifier does not support voice control.
What it is: Indicates whether the humidifier can be operated through a compatible voice assistant.
When it matters: Voice control is useful for hands-free adjustment and smart-home routines.
Importance: MEDIUM
Good value: yes
Dreo Smart Humidifier HM306S 3L supports voice control; the average humidifier does not support voice control.
Hygrostat included
Dreo Smart Humidifier HM306S 3L has a hygrostat; the average humidifier has no hygrostat.
What it is: Whether the humidifier can sense room humidity and regulate its output automatically.
When it matters: A hygrostat helps maintain a chosen humidity target without constant manual adjustment or unnecessary operation.
Importance: HIGH
Good value: yes
Dreo Smart Humidifier HM306S 3L has a hygrostat; the average humidifier has no hygrostat.
Dedicated aroma compartment
Dreo Smart Humidifier HM306S 3L includes a dedicated aroma compartment; the average humidifier does not include a dedicated aroma compartment.
Includes dedicated aroma hardware such as a tray, pad, drawer, or compartment.
What it is: Indicates whether the humidifier has a separate compartment for aroma pads or essential oils.
When it matters: A dedicated compartment keeps fragrance media separate from the main water tank.
Importance: LOW
Good value: yes
Dreo Smart Humidifier HM306S 3L includes a dedicated aroma compartment; the average humidifier does not include a dedicated aroma compartment.
Display included
Dreo Smart Humidifier HM306S 3L has a display; the average humidifier does not have a display.
What it is: Whether the humidifier has a display for settings and status information.
When it matters: A display makes humidity, mode and timer information easier to check.
Importance: LOW
Good value: yes
Dreo Smart Humidifier HM306S 3L has a display; the average humidifier does not have a display.
10 % RH lower target humidity
Dreo Smart Humidifier HM306S 3L supports a lower target humidity setting than the average humidifier (30% RH vs 40% RH).
What it is: The lowest relative-humidity target the user can select.
When it matters: A lower minimum target provides more flexibility in damp climates or rooms where a modest humidity level is preferred.
Importance: LOW
Good value: Up to 30% RH
Dreo Smart Humidifier HM306S 3L supports a lower target humidity setting than the average humidifier (30% RH vs 40% RH).30 % RH vs 40 % RH
10 % RH higher target humidity
Dreo Smart Humidifier HM306S 3L supports a higher target humidity setting than the average humidifier (90% RH vs 80% RH).
What it is: The highest relative-humidity target the user can select.
When it matters: A higher maximum target offers more range for very dry conditions, plant rooms, or specific humidity needs.
Importance: LOW
Good value: At least 80% RH
Dreo Smart Humidifier HM306S 3L supports a higher target humidity setting than the average humidifier (90% RH vs 80% RH).90 % RH vs 80 % RH
3.1 dB lower maximum noise
Dreo Smart Humidifier HM306S 3L is quieter at maximum output than the average humidifier (30 dB vs 33.1 dB).
What it is: The highest stated operating sound level across normal humidification modes.
When it matters: A lower maximum noise level is better for bedrooms, nurseries, calls, and light sleepers.
Importance: HIGH
Good value: Up to 35 dB
Dreo Smart Humidifier HM306S 3L is quieter at maximum output than the average humidifier (30 dB vs 33.1 dB).30 dB vs 33.1 dB
Hygrostat included
Dreo Smart Humidifier HM306S 3L has a hygrostat; the average humidifier has no hygrostat.
10 % RH lower target humidity
Dreo Smart Humidifier HM306S 3L supports a lower target humidity setting than the average humidifier (30% RH vs 40% RH).
10 % RH higher target humidity
Dreo Smart Humidifier HM306S 3L supports a higher target humidity setting than the average humidifier (90% RH vs 80% RH).
3.1 dB lower maximum noise
Dreo Smart Humidifier HM306S 3L is quieter at maximum output than the average humidifier (30 dB vs 33.1 dB).
6 hours longer runtime
Dreo Smart Humidifier HM306S 3L runs longer on a single fill than the average humidifier (30 hours vs 24 hours).
Wi-Fi control
Dreo Smart Humidifier HM306S 3L supports Wi-Fi control; the average humidifier does not support Wi-Fi control.
Voice control supported
Dreo Smart Humidifier HM306S 3L supports voice control; the average humidifier does not support voice control.
Dedicated aroma compartment
Dreo Smart Humidifier HM306S 3L includes a dedicated aroma compartment; the average humidifier does not include a dedicated aroma compartment.
Display included
Dreo Smart Humidifier HM306S 3L has a display; the average humidifier does not have a display.
9.68 cm shorter body
Dreo Smart Humidifier HM306S 3L has a lower profile than the average humidifier (19.3 cm vs 28.98 cm).
16.9% lighter
Dreo Smart Humidifier HM306S 3L is lighter than the average humidifier (1.2 kg vs 1.48 kg).
0.01 m longer power cable
Dreo Smart Humidifier HM306S 3L has a longer power cable than the average humidifier (1.5 m vs 1.51 m).

Why is Dreo Smart Humidifier HM306S 3L worse than the average humidifier?

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5 W higher power draw
Dreo Smart Humidifier HM306S 3L draws more power than the average humidifier (29 W vs 24 W).
3.13 m² less room coverage
Dreo Smart Humidifier HM306S 3L covers smaller rooms than the average humidifier (27.9 m² vs 31 m²).
0.35 L smaller water tank
Dreo Smart Humidifier HM306S 3L has a smaller water tank than the average humidifier (3 L vs 3.35 L).
3.8% lower humidification rate
Dreo Smart Humidifier HM306S 3L delivers a lower humidification rate than the average humidifier (250 ml/h vs 260 ml/h).
6.35 cm wider body
Dreo Smart Humidifier HM306S 3L has a wider body than the average humidifier (25.9 cm vs 19.555 cm).
1.05 cm deeper body
Dreo Smart Humidifier HM306S 3L has a deeper profile than the average humidifier (19.3 cm vs 18.25 cm).
6.35 cm wider body
Dreo Smart Humidifier HM306S 3L has a wider body than the average humidifier (25.9 cm vs 19.555 cm).
What it is: The humidifier’s side-to-side width.
When it matters: A narrower humidifier takes up less space on a bedside table, desk or shelf.
Importance: MEDIUM
Good value: Up to 20 cm
Dreo Smart Humidifier HM306S 3L has a wider body than the average humidifier (25.9 cm vs 19.555 cm).25.9 cm vs 19.555 cm
5 W higher power draw
Dreo Smart Humidifier HM306S 3L draws more power than the average humidifier (29 W vs 24 W).
What it is: The humidifier’s maximum rated electrical power draw.
When it matters: Lower power draw can reduce electricity use, especially when the humidifier runs for many hours each day.
Importance: MEDIUM
Good value: Up to 25 W
Dreo Smart Humidifier HM306S 3L draws more power than the average humidifier (29 W vs 24 W).29 W vs 24 W
3.13 m² less room coverage
Dreo Smart Humidifier HM306S 3L covers smaller rooms than the average humidifier (27.9 m² vs 31 m²).
What it is: The largest room floor area the humidifier is recommended to cover.
When it matters: A larger coverage rating is important for open-plan spaces and larger bedrooms or living rooms.
Importance: HIGH
Good value: At least 40 m²
Dreo Smart Humidifier HM306S 3L covers smaller rooms than the average humidifier (27.9 m² vs 31 m²).27.87 m² vs 31 m²
0.35 L smaller water tank
Dreo Smart Humidifier HM306S 3L has a smaller water tank than the average humidifier (3 L vs 3.35 L).
What it is: The usable amount of water the humidifier’s reservoir can hold.
When it matters: A larger tank generally needs fewer refills and can support longer operation between top-ups.
Importance: HIGH
Good value: At least 4 L
Dreo Smart Humidifier HM306S 3L has a smaller water tank than the average humidifier (3 L vs 3.35 L).3 L vs 3.35 L
1.05 cm deeper body
Dreo Smart Humidifier HM306S 3L has a deeper profile than the average humidifier (19.3 cm vs 18.25 cm).
What it is: The humidifier’s front-to-back depth.
When it matters: A shallower humidifier needs less usable surface depth on a table or shelf.
Importance: MEDIUM
Good value: Up to 20 cm
Dreo Smart Humidifier HM306S 3L has a deeper profile than the average humidifier (19.3 cm vs 18.25 cm).19.3 cm vs 18.25 cm
3.8% lower humidification rate
Dreo Smart Humidifier HM306S 3L delivers a lower humidification rate than the average humidifier (250 ml/h vs 260 ml/h).
What it is: The maximum amount of water the humidifier can release into the air per hour.
When it matters: A higher rate raises room humidity faster and is more useful in dry or larger spaces.
Importance: HIGH
Good value: At least 300 ml/h
Dreo Smart Humidifier HM306S 3L delivers a lower humidification rate than the average humidifier (250 ml/h vs 260 ml/h).250 ml/h vs 260 ml/h
28.6% more expensive
Dreo Smart Humidifier HM306S 3L is more expensive than the average humidifier (£45 vs £35).
Dreo Smart Humidifier HM306S 3L is more expensive than the average humidifier (£45 vs £35).£45 vs £35

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Third-party reviews

United Kingdom

United States

(Reviews last updated: August 2026)

What customers like about Dreo Smart Humidifier HM306S 3L?

Whisper-quiet operation at only 26 dB in sleep mode, making it ideal for bedrooms
Convenient top-fill design allows easy refilling without flipping the water tank or spilling
Ultrafine ultrasonic mist evenly covers up to 300 square feet without dampening surrounding furniture
Excellent smart features including accurate room humidity tracking, custom targets, and seamless remote control via the app
Long continuous runtime of up to 30 hours on a single fill
Includes a dedicated aroma tray for essential oils and a built-in customizable ambient night light
The 360-degree rotating nozzle offers great flexibility in directing the mist output

What customers dislike about Dreo Smart Humidifier HM306S 3L?

Lacks internal Wi-Fi memory, requiring the device to re-sync with the app whenever it is unplugged and moved to a different room
The 3-liter water capacity is relatively small and may require more frequent refills compared to larger 4L or 6L models
Requires regular, diligent maintenance every few days to prevent mold and mineral buildup
The integrated humidity sensor can occasionally display unreliable or inconsistent readings compared to dedicated external sensors

Expert reviews

bobvila.com

28/08/2025

Summary of the review

Dreo Smart Humidifier Review - Tested by Bob Vila

The Bob Vila review praises the Dreo HM306S Smart Humidifier for its budget-friendly price, 3-litre tank with 30-hour runtime, fine mist, and quiet, app-controlled operation, making it ideal for spaces up to 300 square feet. Key pros include the aromatic tray, easy cleaning, and robust app functionality, while the primary con is the lack of a Wi-Fi memory chip, requiring re-syncing to the app after unplugging.

consumerreports.org

N/A

Summary of the review

Dreo HM306S Humidifier Review - Consumer Reports

The Consumer Reports review of the $49.99 Dreo HM306S ultrasonic humidifier highlights excellent overall performance for spaces up to 300 square feet, featuring a built-in humidistat, programmability, a nightlight, and a low $0.89 overnight operating cost. Notable drawbacks include a strict requirement for weekly maintenance and a limitation to cool-mist only operation. For the full, detailed review, visit Consumer Reports.

etm-testmagazin.de

23/01/2026

Summary of the review

Dreo Humidifier 306 Review 2026

In its 2026 review, ETM Testmagazin rated the Dreo Luftbefeuchter 306 "Very Good" (92/100), highlighting it as an efficient, quiet (26 dB), and compact ultrasonic humidifier for medium-sized rooms. Pros include a 3-liter top-fill tank, aromatic tray, and intelligent auto-mode, while cons focus on the plastic construction, lack of a base timer, and non-customizable LED lighting.

haus-garten-test.de

01/09/2025

Summary of the review

DREO 306 Humidifier Review - House & Garden Test

The review by Haus & Garten Test rates the DREO Luftbefeuchter 306 an excellent 1.4 ("sehr gut") for its performance in mitigating dry indoor air during the heating season. Weighing 1.2 kg with a 29W power output, the compact ultrasonic device features a convenient 3-liter top-fill water tank, a quiet operating volume of 26 dB, a runtime of up to 30 hours in sleep mode, and an integrated aroma function. Downsides noted in testing include a basic plastic construction and an ambient color-changing LED light that lacks manual color selection.

homeandsmart.de

06/12/2024

Summary of the review

Dreo Humidifier Review – Top Ultrasonic Models

The home&smart review identifies the Dreo Smart Humidifier as a user-friendly, 4-litre ultrasonic device, praising its top-fill design for easy maintenance and seamless app integration for advanced scheduling. Key advantages include quiet operation and adaptable lighting, while the primary limitation is the restricted on-device control panel, which lacks the advanced automation options available in the app.

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