To find the best oil diffusers, 24 InStyle editors tested 24 oil diffusers for design, noise level, ease of use, features, performance, and value.

Total relaxation is just one deep inhale of a luxury spa-like scent away.

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Smelling mood-boosting oils can help melt your worries away, giving your brain a gentle nudge to remind it to loosen up a bit. Whether you opt for stress-reducing bergamot or uplifting zing of peppermint, aromatherapy essential oils can help your mind and your body feel more at ease, especially after a long or stressful day. Yet, the diffuser you pair it with is just as important as the oil itself. 

Essential oils are most effective when used as part of a holistic approach to relaxation and sleep, which includes good sleep hygiene, a relaxing bedtime routine, and stress management practices, says Alyssa Scolari, a burnout expert, licensed counselor, and owner of See You Through It Counseling. Ultimately, though, using a diffuser with scented oils is like having a personal relaxation assistant, helping to create a calming oasis in your space.

We’re all about a zen moment, and we spent more than 2,500 hours testing 25 of the most popular and best-selling oil diffusers currently available. Over the three-week testing period, we evaluated each one for specific elements, including design quality, noise level, abundance of helpful features, simplicity of set-up, value, and most importantly, its overall performance (in spaces big and small). After comparing our notes and scores, these 16 were the top-performing oil diffusers we recommend.

Our Top Picks Best Overall: Canopy Waterless Diffuser at Amazon ($65) Jump to Review Best Budget: Homeweeks Aromatherapy Essential Oil Diffuser at Amazon ($13) Jump to Review Best Ceramic: Vitruvi Stone Essential Oil Diffuser at Nordstrom ($123) Jump to Review Best Electric Diffuser: Better Homes & Gardens 3-Piece Diffuser Set at Walmart ($27) Jump to Review Best for Small Rooms: Soicare Cordless Oil Diffuser at Amazon ($36) Jump to Review Best for Sleep: Opalhouse Ceramic Oil Diffuser at Target ($26) Jump to Review Best Cordless: Vitruvi Diffuser at Amazon ($199) Jump to Review Best for Large Rooms: InnoGear Essential Oil Diffuser at Amazon ($17) Jump to Review Best Essential Oil Diffuser: Asakuki Rock Essential Oil Diffuser at Amazon ($29) Jump to Review Best Design: Seasons Aero SM Nebulizing Diffuser at Nordstrom ($148) Jump to Review

Best Overall

Canopy Waterless Diffuser

View On Amazon $65 View On Getcanopy.co

Why We Love It: Out of the 24 oil diffusers we tested, the Canopy Aroma Diffuser reigned supreme for its minimalistic design, mild sound, versatility, and overall value. The waterless, mistless diffuser features three fan settings with accompanying indicator lights for slow, medium, and fast. And although the hum intensifies with higher fan settings, we hardly noticed it, and actually appreciated the soft whirring at night, along with the not-too-bright lights that turn off automatically after settings are selected, so as not to disturb sleep if you were to place it in a bedroom.

Who It's For: Unlike some diffusers made of plastic, this one isn't an eyesore—it comes in three core colors that'll elevate any room and match most design aesthetics, including our boho style. Its compact size suited our living room without adding to any clutter, but it's also small enough to fit on a bathroom sink so long as there's an outlet available.

Our Trick: In the morning, drip three drops of an energizing scent onto the puck and turn on the fan to elicit a mild aroma that lasts a few hours. After it fades, switch to a wind-down scent to take you through the end of the day.

Type: Evaporative｜Materials: Natural diatomite｜Aromatherapy: Yes｜Portable: No｜Power: Corded electric｜Run Time: 15 days｜Timer: No｜Auto-Shut Off: No｜Size: 4 x 4 x 4.2 inches

Best Budget

Homeweeks Aromatherapy Essential Oil Diffuser

View On Amazon $13

Why We Love It: At only $12, this essential oil diffuser was a steal, effectively scenting every room we placed it in including our living room, office, and bedroom. The scent would also linger long after the diffuser stopped running, which we were pleased about. Adding water and oil to the diffuser took only a matter of seconds and we didn't experience any spillage. We also found it easy to navigate the settings, as the diffuser only has two intuitive control buttons: one for the lights and one for the diffuser. 

Who It's For: There are two mist settings to choose from: three hours in continuous mode or six hours in intermittent mode. In both, we couldn't detect any noise on the device whatsoever. The mist was also very light; we could only see it if we were within three to five feet of it.

Our Trick: We're fans of the wood element on the base of this model as well as the fact that we could choose from seven LED light colors based on our mood. The device also has an option of turning the lights off altogether, which can be helpful for sleeping. All in all, we found it peaceful having this diffuser on and running, especially while working.

Type: Ultrasonic｜Materials: Polypropylene｜Aromatherapy: Yes｜Portable: Yes｜Power: Corded electric｜Run Time: 6 hours｜Timer: 3 hours in continuous mode or 6 hours in intermittent mode (30 seconds on, 30 seconds off)｜Auto-Shut Off: Yes｜Size: 6.61 x 4.72 x 4.72 inches

Best Ceramic

Vitruvi Stone Essential Oil Diffuser

View On Nordstrom $123 View On Havenwellwithin.com View On Crate & Barrel $123

Why We Love It: Vitruvi is a popular oil diffuser brand with a loyal fan base, and after trying it ourselves we can confirm this ceramic model lives up the hype. Made of a sandy, textured ceramic, the design of this diffuser blew us out of the water: Resembling a small artisanal terracotta vase, it gives expensive energy, especially on our bedroom vanity next to perfume bottles, gold jewelry, makeup, magazines, and a large gold circle mirror. While the ceramic cover has a good weight to it, it's still portable enough that we could move it around our space (or from room-to-room) compared to larger, clunkier machines. It's very easy to control and use, with clearly labeled buttons for the timer, mist, and light settings. We toggled between full brightness in the morning, dim brightness in the late afternoon, and no light when we went to sleep.

Who It's For: Unlike some diffusers that have a bubbly, rolling noise, this diffuser is essentially silent when on the lightest setting spanning four hours (what we used most of the time). The full eight-hour mist setting had a very faint, gentle whooshing-like sound, but we only noticed it when the room was completely silent and even so, we had to consciously listen for it. And with care instructions so relaxed they're borderline neglectful, say no more, we're in.

Our Trick: We don't think our diffuser could hold 70mL of water, regardless of what the user manual said, and after a few spills, we discovered a shot glass-size worth of water is the sweet spot if you like to keep your floors dry.

Type: Ultrasonic｜Materials: Ceramic｜Aromatherapy: Yes｜Portable: Yes｜Power: Corded electric｜Run Time: 4 to 8 hours｜Timer: 4/8 hours｜Auto-Shut Off: Yes｜Size: 5 x 5 x 5 inches

Best Electric Diffuser

Better Homes & Gardens 3-Piece Diffuser Set

View On Walmart $27

Why We Love It: For an electric diffuser that takes up a minimal amount of space, offers light features, and is quieter compared to other models, nothing beats this one from Better Homes & Gardens. We could still smell the oils when we were standing 10 feet away from it—surprising given its small size. We also love that it doesn’t look like a typical diffuser, but more like a charming candle holder than an oil diffuser, thanks to the flickering light inside. To get started, we removed the cover and reservoir cap, added water and then dropped in the recommended 10 drops of an essential oil (it came with two, mint and lavender), put the cap and cover back on and pressed power on.

Who It's For: Anyone who appreciates a foolproof power system and easy, infrequent care are a great fit for this diffuser. Cleaning the basin was a cinch because it's so compact, only needing one quick swipe of a microfiber cloth.

Our Trick: We could hear a slight hum and a trickle of water while it was running, which we extremely relaxing, and the perfect level of white noise to fall asleep.

Type: Ultrasonic｜Materials: Not listed｜Aromatherapy: Yes｜Portable: Yes｜Power: Corded electric｜Run Time: 4 hours｜Timer: None｜Auto-Shut Off: Yes｜Size: 5.75 x 5.75 x 6.88 inches

Best for Small Rooms

Soicare Cordless Oil Diffuser

View On Amazon $36

Why We Love It: We think this diffuser from Soicare is best for office spaces and small rooms alike, thanks to its portable size and hefty aroma when you're close to it. The diffuser has three light settings: one bright light, one dim light, and an "off" button. There's a faint hum sound while it's running, but nothing that we could hear over the television, fan, or noise machine while sleeping or relaxing on the couch.

Who It's For: No-nonsense users may appreciate the fairly basic trio of light settings and timer options. Filling this diffuser up was equally simple, so you can fill 'er up and get going.

Our Trick: We love this design, too, and were it not for the buttons, it would look like a fancy ridged vase sitting on top of a table. We placed it in our office and thought it amped up the room nicely, especially during Zoom calls.

Type: Ultrasonic｜Materials: Plastic｜Aromatherapy: Yes｜Portable: Yes｜Power: Corded electric and battery operated｜Run Time: 5 to 7 hours｜Timer: 1, 2, 3 hours｜Auto-Shut Off: Yes｜Size: 3.98 x 3.07 x 6.73 inches

Best for Sleep

Opalhouse Ceramic Oil Diffuser

View On Target $26

Why We Love It: For those who love to run their diffuser overnight, this one from Opalhouse has an eight-hour run time that maintained a soothing ambience in our bedroom while we slept. Using this diffuser was a convenient and an easy process—both the ceramic cover and inner hard plastic cover remove with ease, and the water reservoir is wide, making it easy to fill with water without making a mess. There's also has an easy-to-read "max fill" line that's decently spaced from the top edge of the reservoir—this extra space prevented us from spilling water as we walked from one room to another.

Who It's For: Design lovers will appreciate the ceramic cream-colored vessel dotted with oval cut-outs, allowing a soft glow to peek out. Best of all, it doesn't have any clunky exterior buttons—it's just a smooth, continuous, chic-looking surface—and only the very faint humming noise reveals its true function. The forgetful among us can rely on the automatic shut-off feature once water runs out since it's so quiet, it's easy to set it and forget it.

Our Trick: The water reservoir is large at 300 mL, so we added a few more drops of oil (eight to 10) than usual and the scent filled our living room without being too overpowering (although it did waft into the hallway, because our neighbor complimented the nice, fresh scent).

Type: Ultrasonic｜Materials: Ceramic｜Aromatherapy: Yes｜Portable: No｜Power: Corded electric｜Run Time: 8 hours｜Timer: None｜Auto-Shut Off: Yes｜Size: 6.64 x 5.25 x 5.25 inches

Best Cordless

Vitruvi Diffuser

View On Amazon $199 View On Nordstrom $182 View On Vitruvi.com

Why We Love It: No outlet, no problem. This cordless and portable option from Vitruvi comes with a rechargeable battery and charging pad, so we never had to be without it. Each of the four neutral colorways—black, white, gray, and pink—feature an optional LED ring light for an extra bit of ambiance (and can turn off fully if we're not in the mood).

Who It's For: Clutter-phobes may enjoy the tall, slender design, which hardly took up any space at all, even in our 250-square foot living room or 40-square foot tiny bathroom, while those who want their devices to be sniffed and not heard will like how silent this model is (the light and the wisp of mist were the only indicators it was on). Overall, its modern, stylish aesthetic makes it easy to match to any decor style—great for those who don't have a design eye to begin with.

Our Trick: It's not as simple to fully charge or fill: It took about two hours to reach the max charge (eight hours with the charging pad) and we don't care to admit how many times we accidentally tilted the basin after refilling, splashing water all over our floors, so we kept it stationary and tucked away in our kitchen, where messes are more forgiving and outlets more abundant.

Type: Ultrasonic｜Materials: Plastic｜Aromatherapy: Yes｜Portable: Yes｜Power: Rechargeable battery｜Run Time: 8 hours｜Timer: 4/8 hours｜Auto-Shut Off: Yes｜Size: 9 x 4.6 x 4 inches

Best for Large Rooms

InnoGear Essential Oil Diffuser

View On Amazon $17

Why We Love It: Large spaces require a diffuser that can pack a punch, and we found this one from InnoGear, despite its 100 mL water reservoir and palm-sized design, up for the task. We ran the diffuser for about five hours at a time and it created an instant fragrance that wafted from our office, to the living room, and even the bedroom down the hall. We didn't hear any sounds coming from this diffuser while using it at night or when sitting right next to it.

Who It's For: Opening and closing it can be done with one hand (and doesn't require any strength to do so), making it great for those with dexterity issues, and with only two buttons on the machine, one for LED lights and one for mist strength, plus an auto-shut off, it's easy for teens and tweens to use.

Our Trick: A con we found on this device is that the water fill line is difficult to see in minimal lighting. But, the good news is that the water line comes with great variety: Exceeding the water line will produce a low mist while staying under the water line produces a larger mist.

Type: Ultrasonic｜Materials: Polypropylene｜Aromatherapy: Yes｜Portable: No｜Power: Corded electric｜Run Time: 3 to 8 hours｜Timer: None｜Auto-Shut Off: Yes｜Size: 3.94 x 3.94 x 5.51 inches

Best Essential Oil Diffuser

Asakuki Rock Essential Oil Diffuser

View On Amazon $29 View On Asakuki.com

Why We Love It: This melon-sized powerhouse from Asakuki diffused the air beautifully with the orange, lavender, and lemongrass oils we put inside. Its compact design didn't take up too much space in our master bedroom, and we loved the sleek white top paired with the rustic wood-looking base. The diffuser has controls for the light and mist on the unit itself, but it also comes with a handy remote (we use it daily!), and even works from up to 16.5 feet away.

Who It's For: We love a hushed tech device, and the noise from this diffuser was so subtle (even on the highest setting) that we could barely notice when it was running, which allowed us to sleep with no issues.

Our Trick: We had a lot of fun bouncing between the bright colored lights and intensities as we switched settings, but we stuck to the more subdued shades in the evenings and frequently even used it as a nightlight.

Type: Ultrasonic｜Materials: Polypropylene｜Aromatherapy: Yes｜Portable: No｜Power: Corded electric｜Run Time: 10 to 18 hours｜Timer: 60/120/180-minute timers｜Auto-Shut Off: Yes｜Size: 6.77 x 6.77 x 5.39 inches

Best Design

Seasons Aero SM Nebulizing Diffuser

View On Nordstrom $148 View On Seasonslife.com View On Saks Fifth Avenue $148

Why We Love It: Portable, waterless, and pretty to look at, we fell in love with how this diffuser from Seasons stood in our kitchen and living room. A definite conversation starter, it comes in four different shades, including a hippie-style matcha green model, which we tested and found to complement our vintage aesthetic perfectly. The small, round shape was also easy to place in our small space that was already full of decor. We didn't run into any issues using the diffuser and we skipped reading the manual since it was pretty easy to distinguish each buttons' usage.

Who It's For: If you prefer to bring your diffuser along with you from room to room, you can! It's powered by a USB charging cable and also comes with a removable strap for easy transporting (this also makes it great for fitness instructors who plan to tote it along to classes). 

Our Trick: We were definitely satisfied with the smell output from this diffuser. We moved it between our kitchen and living room and could still smell it from the opposite room in which it sat. Even in a small house, the scent was never too faint or too overwhelming.

Type: Nebulizing｜Materials: Resin and polypropylene｜Aromatherapy: Yes｜Portable: Yes｜Power: USB｜Run Time: 15 hours｜Timer: 1/2/5 hours｜Auto-Shut Off: Yes｜Size: 3.5 x 6.1 inches

Best Aromatherapy

Organic Aromas Raindrop Nebulizing Diffuser

View On Amazon $99 View On Organicaromas.com

Why We Love It: The device has eight light settings that can change periodically or stay a solid color depending on preference. We found them to be incredibly relaxing, especially when used in darker rooms. We also liked the timer setting because it alternates at two minutes on, then one minute off for two hours straight, which we thought allowed the scents to cascade across our apartment in comfortable doses. While the "spreadability" changed from room to room, the smell was able to reach the entire space when we used it in the middle of our apartment. The mist from the diffuser was noticeable and extended about a foot above, but it still didn't feel like we had a fog machine in the apartment. 

Who It's For: Don't care for a diffuser-humidifier hybrid? If you're after a model that simply scents the space with a pleasing aroma, we find this one from Organic Aromas such a joy. Used in a 1000-square foot apartment, the diffuser is about the size of a one-liter water bottle, making it easy to place on various surfaces in our home. Its beaker-like design is cool, sleek, and most definitely provided a zen and peaceful aura to every room we placed it on.

Our Trick: The only annoyance was the power source, but we turned this con into a pro by plugging it into the bathroom wall (at a safe distance) while relaxing in the tub for an extra zen moment of self-care.

Type: Nebulizing｜Materials: Hardwood｜Aromatherapy: Yes｜Portable: No｜Power: Corded electric｜Run Time: 2 hours｜Timer: 2 minutes on, 1 minute off｜Auto-Shut Off: Yes｜Size: 8.39 x 8.31 x 4.49 inches

Best for Car

InnoGear Car Diffuser

View On Amazon $16

Why We Love It: We loved the portable InnoGear Car Diffuser primarily for making our car smell nice, though we love that it has the humidifying function as well. It has a green power light indicating it's on and an optional LED light that can be set to a solid color or a cycling of rainbow of colors. While in use, we didn't find this model to be noisy—we were still able to listen to music in our car without having the device's fan-like sound overpower it.

Who It's For: We found this to be an easy diffuser to use, and were glad to see that it wasn't overly-complicating and, thus, distracting while driving. There are two mist settings: A continuous mist that diffuses until the water runs out, or an intermittent mist that mists and pauses every 30 seconds. Though we had to walk the diffuser to our house to fill it up, it was easy to add the right amount of water without spilling it on the way back out to the car. We also enjoyed the auto-shut off option that turned off when there was no more water left in the basin.

Our Trick: Because this diffuser is powered by a USB, we plugged it into our laptop during a long drive so we could work and enjoy aromatherapy at the same time. Plus, it compact size was designed to fit inside a cup holder, so it's fully out of the way.

Type: Ultrasonic｜Materials: Polypropylene｜Aromatherapy: Yes｜Portable: Yes｜Power: USB｜Run Time: 3 hours｜Timer: None｜Auto-Shut Off: Yes｜Size: 3.15 x 2.95 x 5.12 inches

Best Essential Oil Humidifier

BZseed Aromatherapy Essential Oil Diffuser Humidifier

View On Amazon $30 View On Ibspot.com View On Walmart

Why We Love It: We love a good two-in-one product, especially if it involves aromatherapy and humidifying, as this one from BZseed does so efficiently. It increases the humidity in the air while perfuming our space with the peppermint, lavender, tea tree oil, and eucalyptus we placed in it. Regardless of what room we were in, we were able to smell the essential oils from about 10 feet away, satisfying our desire for a diffuser with a far reach.

Who It's For: Cleaning the diffuser is simple because it is so wide and easy to access. We rinsed it with a warm water-vinegar combination, and used a cotton swab to clean in the cracks and corners. We also found it super easy to add oil to the diffuser without spilling, thanks to the fact that the water bowl is almost as wide as the whole diffuser.

Our Trick: Something we noticed is that all of the buttons look identical, so we had to check the manual and experiment to figure out what they do. In the end, we discovered that there's one button to cycle through seven light options and another to set the mist level and timer. The diffuser has an indicator light on the buttons as well as an LED light ring that extends around its base. You have the option of dimming and brightening it or turning it off altogether, making it a prime pick for those who may have light sensitivities.

Type: Ultrasonic｜Materials: Plastic｜Aromatherapy: Yes｜Portable: No｜Power: Corded electric｜Run Time: 9 to 14 hours｜Timer: 1/3/6 hours｜Auto-Shut Off: Yes｜Size: 6.2 x 6.2 x 7.4 inches

Best Scented Diffuser

Pura Smart Home Fragrance Device

View On Amazon $50 View On Pura.com

Why We Love It: A plug-in scented diffuser like the Pura Smart Home Fragrance Device Starter Set is unobtrusive yet powerful in its ability to perfume any space. This ranked high when it came to ease of use since all we had to do was pop in two bottles of essential oils, which were provided, and that was it. When the essential oils ran out, we simply popped the bottles out, recycled them, and replaced them. We were able to smell the waterless diffuser while standing 15 feet away and the scent was still present even when we walked into different rooms. Most impressively, the diffuser didn't exhibit any noise whatsoever and we could turn the light off to sleep.

Who It's For: Anyone who loves new tech that feature all the bells and whistles will be a big fan of this minimally designed device. Controlling the diffuser required downloading the accompanying app—from there, we were able to scan the fragrance, choose timer settings, cycle through adjustable LED lights, and create a personalized schedule. The diffuser also has Google Home and Amazon Alexa capabilities. 

Our Trick: Via the app, we set schedules and colors the first day we had it, and have been relaxing ever since instead of fussing with buttons.

Type: Heat｜Materials: Not listed｜Aromatherapy: Yes｜Portable: Yes｜Power: Electric｜Run Time: Not listed｜Timer: None｜Auto-Shut Off: No｜Size: 9.33 x 4.96 x 3.19 inches

Best for Relaxation

Pure Enrichment Crystal Himalayan Salt Rock Lamp & Oil Diffuser

View On Williams-Sonoma $60 View On Pureenrichment.com

Why We Love It: This diffuser from Pure Enrichment is the perfect alternative to a spa day, simultaneously delivering the therapeutic benefits of salt therapy and aromatherapy all at the same time. With only one intensity for diffusing and five options for light, this diffuser features Himalayan pink salt, which comes with detoxifying, soothing benefits. Both buttons are clearly labeled and can be turned on with a simple soft touch—no pressing, clicking, or turning necessary. It also comes with a cute little measuring cup to fill the deep reservoir with water, and if you fill it to the max, you'll get 16 hours of run time.

Who It’s For: Although some may find the gigantic Himalayan salt rock design a little too woowoo, we couldn’t get enough of the wellness-inspired ambiance and kept it on nearly 24/7. It only flipped off when we forgot it was running—that’s how quiet it was.

Our Trick: It's quite bulky and rather heavy, which made our nightstand look cluttered, so we made it a focal point on our coffee table.

Type: Ultrasonic｜Materials: Crystal｜Aromatherapy: Yes｜Portable: No｜Power: Corded electric｜Run Time: 16 hours｜Timer: None｜Auto-Shut Off: Yes｜Size: 7.25 x 7.25 x 8.75 inches

Best Waterless

Eco Modern Essentials Nebulizing Diffuser

View On Ecomodernessentials.com

Why We Love It: If you're turned off by the idea of water diffusers and want to feel better about the air you breathe, this one from Eco will become a welcomed addition to your home. The lack of water in this nebulizing diffuser eliminates the risk of bacteria- and mold-holding particles growing in hard-to-clean areas. We placed this in many different areas of our main floor: A 200-square foot living room, a 100-square foot foyer, and a 150-square foot office. Despite each room having eight-foot ceilings, we could smell the aroma across the entirety of our main floor (a big step up from a candle or plug-in scent). In terms of design, this diffuser has a modern, sleek, and futuristic appeal with just one small on/off button, but if that doesn't mesh with your home decor, it's tiny enough to hide it behind a lamp or picture frame.

Who It's For: One thing that stood out to us was how easy the diffuser was to assemble. Rather than having to count and pour in drops of oil, we just had to screw in the essential oil bottle into the spray head and press the power button to turn it on. The diffuser runs for two hours before automatically shutting itself off, a nice feature that allowed us to leave the house and come back to a nice scent without worry.

Our Trick: This diffuser dispenses scent for 10 seconds every 50 seconds, and it sounds like a small pump is running during those 10 seconds. The noise was pretty quiet nonetheless and we even found ourselves turning it on just to have some background noise throughout the day. The soft noise coupled with the fact that the mist was so fine it was practically invisible makes this a non-obtrusive product for any space in the home.

Type: Nebulizing｜Materials: Not listed｜Aromatherapy: Yes｜Portable: No｜Power: Corded electric｜Run Time: 2 hours｜Timer: 10 seconds off, 50 seconds on｜Auto-Shut Off: Yes｜Size: 2.83 x 5.19 inches

What to Keep in Mind

Type of Diffuser: Ultrasonic, evaporative, heat, and nebulizing make up the lion’s share of diffusers. Ultrasonic diffusers: “They vibrate water and essential oil to create a fine mist that fills the room and gets inhaled into the lungs,” says Dr. Raleigh Duncan, a board-certified chiropractor and the founder Clearlight. This type of diffuser can operate for several hours without needing to be refilled, and is great for bedrooms and living rooms because it can clear allergens in the air to help prevent allergies, says Dr. Duncan. “Ultrasonic diffusers are a very safe method, as oils are diluted and humidity is introduced into the room and lungs at the same time,” says Dr. Duncan. Evaporative diffusers: This type uses absorbent pads, reeds, terracotta, or other similar porous objects to diffuse essential oils into the air of small rooms, powder rooms, or entry halls. They are a much less intense option in both size and scent, so skip this type if you plan to use in a large, wide space. Nebulizing diffusers: Largely considered the most popular option, despite the typically higher cost and frequent care needed. They “diffuse a pure, undiluted oil, meaning the oil remains concentrated in the air for a much longer period of time,” says Dr. Duncan. “This is also a good delivery system for stress reduction and boosting the immune system, since nebulizing diffusers use a stream of air to break essential oils into micro-particles.” Another plus: This diffuser type can usually fill a space quickly and therefore doesn’t need to run long to be effective. Heat diffusers: Small units that plug into a wall outlet or USB charger, they are designed to heat essential oils through an absorbent pad or other medium, explains Dr. Duncan. “These units take up little space and are great at relieving stress, creating ambience, and heightening the senses.” One thing to note: Heat can break down essential oils and change the molecular structure, thereby lessening the healing effect, says Dr. Duncan, who recommends using a heat diffuser in smaller spaces or for “zone” diffusing in larger rooms. 

Aromatherapy: “Aromatherapy taps into the powerful connection between our sense of smell and overall well-being,” says Scolari. “At its core, aromatherapy utilizes essential oils (the concentrated essences extracted from plants) to promote physical, emotional, and mental health.” As Scolari explains, inhaling essential oils through an oil diffuser allows their scent molecules to travel to the limbic system via the nasal passages. “This system influences a range of physiological and psychological responses, including mood and memory,” she says.

Uncomplicated Settings + Features: While essential oils are not regulated by the FDA, using an oil diffuser can be an easy way to add a bit of relaxation, joy, and well-being into your daily life, especially if you’re experiencing burnout. “Burnout is like hitting a wall emotionally and mentally after being under a lot of stress for too long,” says Scolari. “It’s more than just being tired after a busy week; it’s feeling drained, down, and maybe disconnected from things you usually care about.”

This can make everyday stress feel bigger than they are, leading to feelings of anxiety because it feels more difficult to complete tasks. However, diffusing oils can help relax and recharge the brain to help you get back on track. “Setting up your diffuser can be your little signal to pause and breathe, helping to shoo away stress and anxiety,” says Scolari. “Also, some scents are like cheerleaders for your mood and can help make those anxious feelings take a back seat.”

Scent Reach: Be sure to look at the diffuser’s tank capacity (if it’s an ultrasonic unit), square footage capacity, and run time to determine if it’ll effectively fill your space. Generally, the bigger the room, the more oil you’ll need and the longer it’ll take to achieve your desired scent concentration. Diffusing oils, especially lavender, can contribute to better sleep by creating a relaxing atmosphere in your bedroom and helping you wind down. “While the science on the effectiveness of essential oils for sleep remains somewhat uncertain, we know with much more certainty that relaxation before bedtime is essential to achieving healthy sleep,” says Dr. Chester Wu, a psychiatry specialist double board-certified in psychiatry and sleep medicine.

Your Room Size: “Larger rooms are best served by ultrasonic diffusers while the simplicity of evaporative or heat diffusers are best for smaller rooms,” says Dr. Duncan. Nebulizers are best thought of as therapeutic delivery devices: Sit close to it, get the required dosage, and turn the unit off. Diffusing essential oils can stimulate the pathway that connects the olfactory system with the brain’s limbic system, which regulates emotion, says Dr. Wu. Using an oil diffuser can be a strategic way to influence our emotional state, helping you to potentially feel more relaxed.

Design: A diffuser’s design is completely personal preference, but some options that are available are Wi-Fi capabilities, remote control, and faux flames. In any case, Dr. Duncan says that the button function should be obvious, accessible, and easy to understand—there should also be simple and intuitive timer buttons. Look for units that have a minimum of two speed diffusions and that are easy to fill (when it comes to ultrasonic diffusers). Some ultrasonics have rechargeable internal batteries, which make them convenient to place anywhere, Dr. Duncan adds.

Your Questions, Answered

What are the best oils to diffuse in your home?

For sleep, Dr. Wu recommends lavender oil, as it’s “far more studied than any other oil, and so far, has the strongest evidence in support of its efficacy.” Lavender oil also contains compounds like linalool and linalyl acetate, which have soothing properties. “These compounds help decrease anxiety and induce a sense of calm and tranquility, making lavender oil particularly effective in creating a peaceful and relaxing atmosphere,” says Scolari. Other essential oils to look out for are frankincense to reduce inflammation, peppermint to energize, and eucalyptus for clear breathing and pain relief, says Dr. Duncan.

Sandalwood oil, which is commonly used in meditation and religious practices to promote mental clarity and focus, has a warm, earthy scent that can have a soothing effect on the brain's emotional center. "This can help aid in calming racing thoughts and bring about a sense of peacefulness and grounding," says Scolari. "Clary sage oil is a natural chill pill for your body's stress system because it talks directly to the hypothalamus, the part of your brain that decides how much cortisol (your body's stress hormone) to pump out."

Is diffusing essential oils safe for your lungs?

"Some individuals may experience respiratory irritation, especially with prolonged exposure," says Dr. Wu. He recommends using a diffuser for up to 60 minutes and keeping the environment well-ventilated.

Some essential oils can also be toxic to pets as well as children, who have a more sensitive respiratory system. By choosing oils that are safe for the entire household, like lavender, which Dr. Wu says has a better safety profile than others. If you have children in the home with asthma or other respiratory issues, consult your healthcare provider before using an oil diffuser.

How should I clean an oil diffuser?

Ultrasonic diffusers with a water tank can be cleaned by adding 10 drops or more (depending on size of basin) of white vinegar in fresh water and letting it run for a few minutes, says Dr. Duncan, Then just rinse the mixture out and let the basin dry.

To clean a nebulizing diffuser, add a teaspoon of rubbing alcohol to the reservoir and run for five to ten minutes. Heat and evaporative diffusers are best cleaned by using rubbing alcohol and cotton swabs to remove residue from the apparatus, dish, or vessel.

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Michelle Rostamian is a writer covering all things beauty and wellness. For this story, she reviewed insights from the InStyle editorial team, who meticulously tested more than two dozen oil diffusers to find the best ones. She also spoke with Alyssa Scolari of See You Through It Counseling, Dr. Chester Wu, and Dr. Raleigh Duncan for their professional expertise.