Illustration — real photos are on the store page. See photos on Amazon
Levoit Classic 300S Smart Ultrasonic Cool Mist Humidifier, 6 L Top-Fill Tank
A 6 L top-fill tank that runs up to 60 hours and holds the humidity you set — from the unit, your phone or your voice.
Amazon
See today’s price on Amazon
Prices change several times a day, so we don’t show an old one: Amazon always shows the live price, delivery and stock.
We may earn a commission when you buy through our links. It never changes how we rank products. How we make money
At a glance
Our verdict
—If you want a humidifier you can set once and forget, the Classic 300S is our pick: a big tank, a humidity-holding Auto mode, app scheduling and a ≤ 30 dB rating that suits bedrooms. As with any ultrasonic humidifier, hard tap wat...
RightScore appears once live prices from licensed store feeds are connected — we never guess a number.
Read the full verdict60 h
Run time (low mist)
26 W
Rated power
≤ 30 dB
Noise level
4.3 lb
Weight
Best for
- Bedrooms
- Bedtime
- Everyday use
- Home office
Best thing: Large 6 L tank with long run time
Honest catch: Ultrasonic mist can leave white dust with hard tap water — distilled water avoids it
Our verdict
If you want a humidifier you can set once and forget, the Classic 300S is our pick: a big tank, a humidity-holding Auto mode, app scheduling and a ≤ 30 dB rating that suits bedrooms. As with any ultrasonic humidifier, hard tap water can leave fine white dust, so distilled water and regular cleaning are part of the deal.
Why you’ll like it
-
01
Fewer refills: the 6 L tank runs for up to 60 hours on the low mist setting.
-
02
Comfort on autopilot: Auto mode adjusts the mist to keep 40–50% relative humidity, or your own target.
-
03
Control from bed or from work: the VeSync app adds schedules, and it works with Amazon Alexa and Google Assistant.
-
04
Easy to keep clean: pour water straight into the wide top opening — no flipping the tank upside down.
-
05
Bedroom-friendly: rated at 30 dB or less, with a sleep setup that turns the display lights off and an optional night light.
-
06
Aim the mist with the 360° nozzle, and add essential oils to the built-in aroma pad (oils not included).
Great for
- Bedrooms and nurseries in dry climates or heated homes
- Smart-home users who want schedules and voice control
- Anyone tired of refilling a small humidifier every day
Maybe skip it if
- You want warm mist
- You do not want to use distilled water or clean the tank regularly
Where it shines
How well it suits each use, based on its specifications.
- Bedrooms Great
- Bedtime Great
- Everyday use Great
- Home office Good
- Large rooms OK
Pros & cons
Pros
- Large 6 L tank with long run time
- Humidity-sensing Auto mode
- Top-fill design is easy to refill and clean
- Two-year limited warranty
Cons
- Ultrasonic mist can leave white dust with hard tap water — distilled water avoids it
- Cool mist only, with no warm-mist option
Based on the maker’s specifications and published information — every point is checked against a named source.
Where to buy
Stores we link to in US. We show a price only when it is live.
Amazon
Amazon shows the live price and stock
Live price on Amazon
Prices change often, so we send you to Amazon for the current one instead of showing an old price.
We may earn a commission when you buy through our links. It never changes how we rank products. How we make money
More stores and live prices are added automatically as we connect store feeds.
Specifications
General
- Mist type
- Ultrasonic cool mist
- Warranty
- 24 months
Connectivity
- Smart control
- VeSync app, Amazon Alexa, Google Assistant
Design
- Tank capacity
- 6 L
- Top-fill tank
- Yes
- Nozzle
- 360° rotating
Dimensions
- Dimensions
- 9.6 × 7.5 × 13.4 in (24.5 × 19.2 × 34 cm)
Features
- Mist settings
- Low, Medium, High, Auto
- Auto mode target
- 40–50% RH or custom target
- Optional night light
- Yes
Performance
- Run time (low mist)
- 60 h
- Room size (Levoit)
- 215–505 ft² (20–47 m²)
- Noise level
- ≤ 30 dB
Size & weight
- Weight
- 4.3 lb
Power
- Rated power
- 26 W
- Voltage
- 120 V, 60 Hz
Source: RightDeals research · verified 2026-10-10
Our score is on its way
We publish it only once enough real data is in — see how we rank products.
What buyers say
We only show star ratings we are licensed to display. Read verified buyer reviews and photos directly on Amazon.
Questions people ask
How long does a full tank last?
Levoit rates up to 60 hours on the low mist setting. Medium and high mist use water faster, so expect fewer hours there.
What humidity does Auto mode aim for?
By default it adjusts the mist to keep 40–50% relative humidity; you can also set your own target.
Can I use essential oils?
Yes — add a few drops to the built-in aroma pad, not to the water tank. Oils are sold separately.
Sources & method
Researched from the maker’s specifications, the store listing and published information — not lab-tested. We never accept payment for a recommendation.