The 4 Best Aromatherapy Diffusers

Type: Ultrasonic | Measured Run Time: 48 hours

If you're after a diffuser with the capacity to fill a whole room with an aroma and that can run for a long time, you've found it. The ASAKUKI Smart diffuser has the largest capacity of any unit we tested and is ready for action. The ASAKUKI easily connects to your home WiFi network, allowing you to control the diffuser from anywhere in the house via its free app, TuyaSmart. Although the unit itself has the same minimal button layout as many other models, the control offered through the app is impressive. Select your favorite color from the entire spectrum, choose your brightness on a sliding scale from 0-100, and easily adjust the strength of the mister. You can even set up specific schedules and pair them with your Alexa-enabled device to turn on your favorite diffuser mood with just your voice.

Without the powerful app, the ASAKUKI settings work like many other diffusers we tested. The most significant selling point is the exceptional control this unit offers by harnessing the power of today's smart technology. And though we love its thick plume of fragrant mist, it can be a bit excessive for small spaces. It isn't the most chic-looking model in the line-up, but it's also not our least favorite — the woodgrain accents help the ASUKAKI blend in better around your home. This diffuser offers the best coverage, the longest run time, the most control, and integrates easily into your smart home.

Capacity: 700ml
Timer Settings: 1 hour, 3 hours, 6 hours, ON (auto shut off when empty)
Mist Settings: Weak, strong

Includes: Diffuser, adapter, directions, 150 ml measuring cup, optional free app, optional Alexa-enabled voice control

Type: Nebulizing | Measured Run Time: 2 hours

The Raindrop 3.0 is our favorite nebulizing model we tested. This type of diffuser creates pure atomized oils not diluted by water. This elegant glass-topped unit looks great anywhere, with clean, smooth lines, and it's mesmerizing to watch the essential oil vaporizing within and rising slowly out the top. Without the need to dilute your oils, the Raindrop 3.0 quickly fills your space with pure scent, easily covering large rooms without the extra humidity created by ultrasonic devices. This classy-looking diffuser is quiet even on its highest setting and features a simple white LED light and a built-in 2-hour timer. It runs in a cycle of 2 minutes on and 1 minute off to provide even, effective coverage. It's also the only model we tested with a magnetically attached cord to help prevent a disaster if you trip over the cord — though it's not foolproof.

However, the Raindrop 3.0 may seem a little bare-bones if you love bells and whistles. You can choose to have the small white light on or off, and the dial will select your preferred aroma intensity, but that's the extent. This attractive little unit will run for its programmed cycle for 2 hours before shutting off (though the light remains on). While initially considering this a downside, we quickly discovered that the Raindrop is so effective that having it on for more than 2 hours at a time can be overpowering. If you're looking for a simply designed diffuser that offers excellent coverage of pure scent, we think this tasteful model is well worth its price.

Capacity: N/A
Timer Settings: Runs for 2 hours no matter what
Mist Settings: On for 2 minutes, off for 1 minute; intensity dial

Includes: Diffuser, adapter, directions, 2 plastic pipettes, glass pipette

Type: Ultrasonic | Measured Run Time: 30 hours

The Anjou 500ml is the answer if you're looking for subtlety and consistency. This teardrop-shaped aromatherapy diffuser has a unique oil tube inside to distribute essential oils more evenly over time. The oil floats on top in most other models, where it tends to diffuse first; which initially packs a powerful punch but grows weaker the longer the unit runs. By adding your oils to the small glass tube inside, the Anjou evaporates a smaller but more consistent amount of oil throughout its exceptionally long run time. It may take longer before you smell it, but the delicate fragrance lasts longer than most others. It's also one of the few models with a visible difference between the high and low mist settings — many others appear identical in output. A thin light ring wraps around the base's middle, providing an understated accent color that won't blind you in your bedroom at night.

However, this diffuser is rather large. The Anjou is enormous compared to others we tested with similar or even larger capacities. Be sure you like the look of whichever color or woodgrain you purchase, as it isn't easily tucked away out of sight. The lid's inside portion also has a complicated surface area, making cleaning more challenging than most when swapping between scents. And because it prioritizes a slower, more even use of oils, it does take longer to fill your space with that fresh scent. However, the Anjou is an excellent choice to keep your quarters pleasantly refreshing for hours on end if you're after consistency and don't mind the size of this centerpiece.

Capacity: 500ml
Timer Settings: 1 hour, 4 hours, 8 hours, ON (auto shut off when empty)
Mist Settings: Low, high

Includes: Diffuser, adapter, directions, small cleaning brush, extra essential oil tube

Type: Ultrasonic | Measured Run Time: 7.5 hours

The Vitruvi Stone Diffuser is small but absolutely gorgeous. Unfortunately, this elegant diffuser has a tiny 90ml capacity and minimal settings. Depending on how you dilute your oils, you can still get pretty good coverage if you aren't trying to fill your entire 2000-square-foot house. Still, it easily filled our main tester's spacious living and dining room area. Limited timer and light settings keep it simple to use and keep it looking fly in the process. It's even simple to clean; just run it for 30 minutes with a specified white vinegar mixture, and you're good to go.

However, the Vitruvi will likely disappoint if you're looking for a rainbow of color options or a plethora of timers and mist settings. Its narrow band of light has only one color (a peachy orange shade) of a single brightness. And it offers only two usage settings with no option to just turn it ON and walk away. The ceramic stone top is also much easier to break, scratch, or get fingerprinted than the plastic tops of most other diffusers we tested. The cap on the reservoir has a pointy top where the mist escapes, which requires careful alignment with the hole in the ceramic cover. Still, we think it's a great addition to a single room where you can wow your friends and family with its fresh looks and fragrance.

Capacity: 90ml
Timer Settings: 3 hours (continuous mist) or 7.5 hours (intermittent mist)
Mist Settings: Intermittent (30 seconds on, 30 seconds off; 3 hours only) or continuous (7.5 hours only)

Includes: Diffuser, adapter, directions, 200 ml measuring cup

Type: Nebulizing | Measured Run Time: 4 hours

There's much to love about the wood grain base and delicate glass top of the ArOmis Waterless Nebulizer — and plenty of options to match your decor style. This nebulizing diffuser atomizes pure essential oils, offering fast-acting, room-filling scents that ultrasonic units just can't keep up with. Cutting down on some of the extravagances of other models, the ArOmis operates with a single dial, allowing you to adjust your preferred intensity while all other settings remain consistent. Though it's a touch smaller than we had envisioned before buying, we love how it looks just about anywhere around the house, easily filling even the largest spaces with our favorite scents.

If you're hoping for timer options and lights, you'll want to look elsewhere because the ArOmis has neither. Units run for a specified time (ours was 4 hours, but other durations are available) in 10-minute on and 10-minute off intervals. This can be a bit overpowering in small spaces, but it is certainly effective. Our main complaint is loudness. Even on its lowest intensity setting, the vibrations are clearly audible, regardless of whether it's sitting on a wooden desk or directly on a carpeted floor. Its highest setting was difficult to ignore unless it was on the other side of a large room masked by other sounds. If you don't mind some white noise and need a diffuser with a super potent output, the stylishness of this small, sophisticated nebulizing diffuser will surely add some tasteful flair — and aroma — to your space.

Capacity: N/A
Timer Settings: 4 hours (can also purchase units that run for 1 hour, 8 hours, or 12 hours)
Mist Settings: On for 10 minutes, off for 10 minutes; intensity dial

Includes: Diffuser, adapter, directions, plastic pipette

Type: Ultrasonic | Measured Run Time: 20 hours

The Pure Daily Care Ultrasonic is an excellent gift idea if you're searching for the perfect starter kit to give your favorite budding essential oil enthusiast. You get a pretty woodgrain diffuser AND 10 different 10ml bottles of common essential oil for one reasonable price. Also included is a brief description of each oil and some common and preferred uses. An average-sized reservoir and great run-time help the Pure Daily to be a user-friendly choice. Additionally, its buttons and settings are simple to comprehend and easy to use.

For the tech hounds out there, the simplicity of the Pure Daily Care may be underwhelming. It has just one mist setting, and during our testing, the light was inconsistent in whether it turned off when the unit shut off or remained on. The thin neck is also more challenging to clean than most flat-topped models we tested. And the essential oils don't say whether or not they are 100% pure — which is something you definitely want when putting them into your diffuser. The Pure Daily Care might not be elite enough for a hardcore essential oil enthusiast, but it's a great value package as a starter kit or gift.

Capacity: 300ml
Timer Settings: 1 hour, 3 hours, 6 hours, ON (auto shut off when empty)
Mist Settings: Continuous/one level only

Includes: Diffuser, adapter, directions, ten different 10ml bottles of essential oils

Type: Ultrasonic | Measured Run Time: 6 hours

One of several lookalikes on the internet, the URPOWER 2, is a minimalistic aromatherapy diffuser that's uncomplicated to use and inexpensive. Though many diffusers claim to be “whisper-quiet,” the URPOWER is genuinely an exceptionally quiet device. It has minimal options perfect for the essentialist: ON or OFF, and continuous or intermittent mist. Lacking any timers, this little machine simply runs until it's empty, which is around 6 hours using the intermittent setting. The entire translucent device lights up brightly or dimly in seven colors or cycles through the rainbow, making it a solid choice for those with nyctophobia (fear of the darkness.)

The URPOWER is best used in smaller spaces because of its limited capacity and can be an excellent fit for a child's bedroom or even your office at work. However, if you're hoping for a diffuser that can last all night or the whole workday, this isn't it. It's also not the best choice to keep your entire 4-bedroom house smelling fresh, and its limited options may be too limited for some. Additionally, it isn't the most elegant in appearance and has a surprisingly short cord — just 4 feet long. However, the URPOWER is a reliable option for an undersized elementary model that fits in modest spaces and boasts an appealing price tag.

Capacity: 100ml
Timer Settings: ON (auto shut off when empty)
Mist Settings: Intermittent (30 seconds on, 30 seconds off) or continuous

Includes: Diffuser, adapter, directions

Type: Ultrasonic | Measured Run Time: 16 hours

We love how the EQUSUPRO Ultrasonic Cool Mist seems to dance in the dark, but to our dismay, we found its diffusing performance lacking. The colors of the lights in the EQUSUPRO are more vibrant than any other model we tested, giving this blackened metal unit a rich, striking appearance with the lights on or off. Five different possible patterns let you choose a design you love to look at. And for a small 100ml diffuser, we're pleased to report it kept running longer than we expected.

Unfortunately, this long run time was mostly due to the wild inconsistency of how much mist the EQUSUPRO was putting out. While at first, it was a veritable smokestack, filling the room with sweet-smelling scents. After several uses, it started unpredictably oscillating between working precisely as promised and putting out so little mist that it could barely be seen. The design could also be improved upon because you can see the end of the white reservoir funnel poking through the black metal top, ruining its sleek appearance. However, you may find a use for the EQUSUPRO if you're more interested in a cool light than its diffusing capabilities.

Capacity: 100ml
Timer Settings: ON (auto shut off when empty)
Mist Settings: Intermittent (30 seconds on, 30 seconds off) or continuous

Includes: Diffuser, adapter, directions, 150 ml measuring cup

Why Trust GearLab

After spending hours researching dozens of the most interesting and promising models on the market, we narrowed it down to the top 8 aromatherapy diffusers. We enthusiastically purchased them all and pitted them head to head — or nose to nose — to see which ones would come out on top. We filled them to their limits, challenged them to infuse large spaces, and ran them for days at a time. We put them all around our homes day and night to determine where each fits best. If you've felt like every diffuser sounds the same as the last, read on! We're here to illuminate their differences and help you decide the right choice for you.

This review is spearheaded by a two-headed team of testers, Maggie Nichols and Penney Garrett. Maggie is a Grade A gadget fiddler, always tinkering with settings and pushing the limits of every piece of tech she owns. Living with a perpetually dirty adventure dog (and partner!), she appreciates the value of a clean-smelling home and is always trying new methods of making it so. Penney studied botany and clinical herbalism and has worked in several apothecaries, selling and experimenting with various oils. These two have been testing products for GearLab for many years and put their heads together to prod these diffusers and find their limits.

Analysis and Test Results

To test this line-up, we didn't merely plug all the diffusers in, turn them on, and walk away. We broke down exactly what we wanted from an ideal diffuser and tested every aspect in detail. Our process ranged across five comprehensive and mutually exclusive metrics to provide a precise and accurate picture of each model's strengths and weaknesses. Below, we discuss how we did it and which ones excelled where.

Effectiveness

The most important aspect of an aromatherapy diffuser is how well it works. To understand their effectiveness, we considered each unit's coverage, intensity, and humidifying properties. We scientifically tested each diffuser with identical dilutions in the same-sized space to see how quickly they filled the area and if they became overpowering or were too subtle. We measured humidity changes (from ultrasonic units) and scrutinized the many different mist intensity settings.

Nebulizing diffusers take the cake when it comes to filling a space with pure, clean aromas in a short time. Because they don't require dilution of essential oils, they directly atomize pure oils, offering stronger scents. Though they can be overwhelming in very small spaces if left on too long, they can be a lifesaver for easily filling large rooms and quickly creating a “scent garden” wherever they are. We tested several nebulizing models. The ArOmis is one of the most potent diffusers of any kind that we tested. The 10 minutes on, 10 minutes off cycle rapidly covers your living space with fragrance. The Raindrop 3.0 is slightly more subtle and more evenly distributed, with its 2 minutes on, 1 minute off cycle, and is our overall favorite nebulizing model.

Providing the most consistent coverage of any ultrasonic model we tested is the Anjou 500ml. It has an oil reservoir on one side of the water reservoir that evenly dispenses oil as the water level goes down. This provides a steady level of fragrance for as long as the water and oil supplies last, rather than running through all the oil floating on top of the water first, as most others tend to do. It's also one of the only models we tested where we could actually see the difference between high and low mist settings.

The ASAKUKI Smart diffuser is also particularly effective, emitting a large, evident plume of mist for as long as the tank has water. It works very well to cover large spaces and adds humidity to the air when used in smaller rooms.

Ease of Use

We considered numerous factors for testing ease of use, including capacity, ease and frequency of refilling, and the included directions. We navigated settings while deciphering cryptic direction booklets and online informational videos. We tried every combination of features and settings we could just to see what they would do. And we also accounted for the intuitiveness of each, as we're just as guilty as everyone else for throwing the instruction manual away after a few days of ownership.

With its functional and straightforward added technology, the AKASUKI is a breeze to use. It is easily controlled with an app on your smartphone or by voice using your Alexa-enabled device — as long as you have a WiFi connection. The Anjou 500ml is easy to open and close and has a reasonably large capacity that requires less frequent filling.

A few of these aromatherapy diffusers are very simple to use due to a limited range of features. The URPOWER 2, Vitruvi Stone Diffuser, and EQUSUPRO Ultrasonic Cool Mist are very simple to operate because they lack timers, mist functions, and/or light settings. Additionally, all three of them have shorter cords on their adapters, forcing them to be closer to an outlet to function. The nebulizing models we tested, the Raindrop 3.0 and ArOmis, are also very straightforward, each with a simple dial to control their power and mist intensity.

Run Time

To score each contender in this metric, we tested and measured every power function they have. From preprogrammed timers to running each until they dried out and shut off, we pushed them to their limits of continuous use. We also considered what options each has available to the consumer and how useful those time intervals and mist options are to the average user.

Taking home the grand prize in this metric is the ASUKAKI. As the diffuser with the largest capacity in our tests, we expected it to outlast the rest when left to run dry. However, we didn't expect it to pump out a consistent cloud for over 48 straight hours, but that's precisely what it did. That alone is incredibly impressive. Additionally, the ASUKAKI has similar timer options to many others we tested and equivalent high/low mist modes.

With an impressive longevity score, the Anjou 500ml ran for over 30 hours in our laboratory experiments. On top of that, it has our favorite timer settings of 1, 4, and 8 hours — enough to get most of us through a full night of sleep or a complete workday (or nearly so). Another notable option is the Pure Daily Care, lasting over 20 straight hours, despite having a smaller tank of just 300ml.

Ease of Cleaning

As much as we all wish we'd never have to clean anything again for the rest of our lives, that, unfortunately, is not the case. Especially for a machine that you're jamming oil into over and over again, the ability to clean it is essential. We tested each one's ease of cleaning by, well, cleaning them. We did our best to scrub every nook and cranny according to their directions. We also evaluated those directions (if they existed) against our expansive knowledge of diffuser care. And we assessed how easy or challenging each one is to take apart and put back together.

According to its instructions, and assuming you have white vinegar on hand, the Vitruvi is the easiest diffuser to clean. Its manual simply directs you to make a solution of water and vinegar and run it through the machine for 30 minutes. Even cleaning it with a cloth by hand is relatively simple — though the small neck at the top of the water chamber can be a little tricky without a cotton swab or tightly twisted paper towel.

The AKASUKI has a large base that is easy to wipe down, but it suffers from a more complicated lid with small spaces that is very difficult to cram a cloth into. Similarly, the Anjou's base is easy to clean, but the busy has many small crevices and slots that help create mist but are extremely difficult to clean. However, cleaning the bases is far more important than cleaning the lids - though you should strive to clean both regularly.

Features and Aesthetics

Assessing the aesthetic appeal of any product is a very subjective matter. However, we included some baseline characteristics to create an accurate assessment of both looks and exceptional features. We considered the number of colors and patterns each is offered in, particularly favoring woodgrains and other natural-looking exteriors. We compared how noisy they are relative to one another and other household noises, and paid attention to if those noises were the motor or the bubbling water. We took note of the lights — colors, brightness options, and available settings — and noted what additional materials they all come with.

It's tough to find a room or space where the elegance and stylishness of the Raindrop 3.0 and ArOmis don't look great. Though different shapes, both these nebulizing diffusers feature simple wooden bases with clean lines and graceful glass tops in shapes that are both wonderful to look at and offer exciting views into the inner workings of the atomization process. While both these models are a bit lacking in features, they are some of our favorites in terms of aesthetics. The Raindrop has one extra feature not found on any other model we tested — a magnetically attached power cord. Though it's not a flawless solution, this cord is much more likely to detach from the base when tripped over or yanked on, potentially saving the glass on top of the unit from crashing to the floor.

The Vitruvi is the hands-down favorite ultrasonic model among our testers when it comes to sheer looks. This ceramic stone diffuser looks classy and classic. Available in four colors, it easily fits into just about any home decor. It's also exceptionally quiet, and though it has only a single light color and brightness, we find the peachy glow pleasant and easy to appreciate. Also standing out in this category is the EQUSUPRO for its unique metal cover and exceptionally vivid lighting colors. We frequently found ourselves just watching them scroll through a full spectrum of vibrant hues for minutes at a time.

Also scoring well is the ASAKUKI, with its WiFi compatibility. It has a woodgrain accent and pleasing cube shape that makes it a good fit in various rooms and workspaces. Notable as well is the Pure Daily Care, which is the only one we tested to come with essential oils — though those oils don't claim 100% purity, which we advise using.

Conclusion

While each of the diffusers we tested is fully capable of spreading the scent of your favorite essential oil through the air, they are all different from one another and have unique qualities that make some better suited for large areas, some ideal for a work cubicle, and others a great nightlight or a thoughtful gift. No matter what aromatherapy diffuser you ultimately decide is the best choice for you, treating it kindly with 100% pure oils and regular cleaning will help it to be more effective and last longer.