ConsFirst / Humidifiers / Compare
Blueair InvisibleMist Humidifier H35i vs Levoit Classic 300S Ultrasonic Smart Humidifier
Which one has the downsides you can live with?
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The short answer
Blueair InvisibleMist Humidifier H35i ranks higher (#3 vs #4 of 8) and scores better on easy cleaning, running cost, durability. Levoit Classic 300S Ultrasonic Smart Humidifier wins on humidifying power, quietness, tank & runtime.
The biggest complaint about the Blueair InvisibleMist Humidifier H35i is small tank; for the Levoit Classic 300S Ultrasonic Smart Humidifier it's leaks. Pick the one whose catch bothers you less.
Side by side
| Blueair InvisibleMist Humidifier H35i | Levoit Classic 300S Ultrasonic Smart Humidifier | |
|---|---|---|
| Rank in humidifiers | #3 | #4 |
| Price tier | $$ | $$ |
| Type | Evaporative | Ultrasonic |
| Amazon 1–2★ share | 14% | 10% |
| Overall score | 3.7 | 3.6 |
| Humidifying power | 3.0 | 4.0 |
| Easy cleaning | 5.0 | 3.0 |
| Quietness | 3.5 | 4.5 |
| Tank & runtime | 3.0 | 4.0 |
| Running cost | 4.0 | 3.5 |
| Durability | 3.5 | 2.5 |
Price tiers: $ under $60 · $$ $60–150 · $$$ over $150. Highlighted = clearly better (a score gap of 0.3 or more, or a 1–2★ share at least 3 points lower). Scores are explained, with sources, on each product's page.
Top complaints
Blueair InvisibleMist Humidifier H35i
- Small tank
Wirecutter says the 0.9-gallon tank falls just below its 1-gallon guideline, so larger rooms or very dry climates will mean more refilling.
Source: Wirecutter - Filter cost
The Spruce says the wick filter costs about $30 every six months or so, and Wirecutter says it is designed for a roughly six-month replacement cadence.
Source: The Spruce, Wirecutter - Louder than ultrasonic, and no visible mist
Wirecutter notes its fan makes it louder than an ultrasonic model, though still well below conversation level. The Spruce reports that testers of evaporative models, including this one, wished they could see mist to know it was working.
Source: Wirecutter, The Spruce
Levoit Classic 300S Ultrasonic Smart Humidifier
- Leaks
Leakage is a negative aspect in Amazon's review summary (607 of 668 mentions negative), with owners saying it leaks everywhere. Wirecutter says Amazon reviewers and a few staffers found the tank started leaking after a few months, some pointing to the float-valve rubber stopper.
- Breaks within months
Durability is negative on Amazon (411 of 570 mentions), with owners reporting units that broke within about three months or turned off constantly.
- Crevices that are tedious to clean
Good Housekeeping's only listed con is a base with many cracks and crevices. Wirecutter found the area around the mist chimney and the water channel in the basin tricky to scrub. The Spruce, however, found it easy to clean.
- Shorter runtime than claimed; clunky app
CNN Underscored's 6 L tank lasted about 39 hours on low against Levoit's 60-hour claim, and it struggled in medium-size rooms. CNN also called the VeSync app buggy, and Wirecutter found the icon-only buttons counterintuitive.
- White film with tap water
Wirecutter says you should use distilled or demineralized water, or the mist can leave a chalky white film across the room.
Source: Wirecutter
Who should pick which
Pick the Blueair InvisibleMist Humidifier H35i if
People worried about mold and slime
Bedrooms (no wet mist or fog)
Tap-water users who want an app
Skip it if: You want to see mist to know it's working; You need a big tank for a large room; You want near-silent operation
Pick the Levoit Classic 300S Ultrasonic Smart Humidifier if
Bedrooms and medium rooms
Quiet overnight use
App and voice control on a mid-range budget
Skip it if: A leak onto furniture or floors would be a disaster; You hate scrubbing crevices; You won't use distilled water
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