Three best essential oil diffusers

Michael Pollick

Essential oil diffusers use ultrasonic vibrations to generate a cold mist and don’t leave behind ashes, chemical propellants, or wax residue.

The practice of aromatherapy can be traced back thousands of years, but the preferred methods of delivering fragrance to the air have changed over time. The smoke from a burning incense candle gave way to the steam of a potpourri pot, then the flame of a scented candle led to the mist of an aerosol air freshener. Now one of the most popular aroma delivery systems involves a cool mist created by ultrasonic waves passing through a mixture of essential oils and water. Welcome to the world of essential oil diffusers.

Essential oil diffusers eliminate the need for open flames, heated steam, smoldering wood, or chemical propellants. You place a few drops of fragrant oil extract in a water-filled reservoir and allow the ultrasonic wave generator to create microscopic droplets. This mist evaporates quickly, leaving behind a pleasant aroma and minimal residue.

There are many essential oil blends available on the market, and an array of diffuser units that blend in with almost any décor. The following guide can help you find the essential oil diffuser that's right for you.

Considerations when choosing essential oil diffusers

Purpose: The first consideration is the purpose of adding an essential oil diffuser to a specific space. Professional aromatherapists often select fragrances based on a client's specific needs or preferences. Those who are seeking a safer form of air purification for a public space will want to consider essential oils that are universally appealing or powerful enough to address strong odors.

Cost: It's also important to consider the cost of essential oils. Many models include a few samples of basic oil blends, but these will eventually need to be replenished. It pays to shop around for the most affordable selection of oils. The diffuser itself might be extremely affordable, but the proprietary essential oils could be very expensive. Some models can process a variety of brands, but others cannot.

Maintenance: Some owners want a diffuser with a larger reservoir because they can set it in motion in the morning and turn it off at the end of the day. Diffusers with smaller tanks must be replenished several times throughout the day to remain effective. This works out well for short-term aromatherapy sessions but not so well for use in a public waiting room or restroom.


Essential oil diffusers come in all shapes and sizes, but all of them have some important features in common.

Reservoir capacity: All diffusers contain a storage tank where water and essential oils mix. A larger reservoir generally means a longer running time between refills, which can be a good thing when the unit is located in a public space. Some users might prefer a smaller reservoir for short aromatherapy sessions at home, or they might want the flexibility of changing oils more frequently.

Aesthetic design: Because essential oil diffusers are often on public display, they tend to feature artistic or sculptural designs. Even the most basic and functional models use pastel colors and sleek, modern elements. Higher-end models can resemble vases or decorative pottery. Shoppers should consider the form as well as the function when it comes to essential oil diffusers.

Lighting: Aromatherapy sessions aren't focused solely on the effects of fragrance. There are also visual elements that enhance the overall experience. Many diffusers include LED lights that can be programmed to create soothing patterns, change colors, or otherwise set a particular mood.

Humidification and other features: Some essential oil diffusers can also add moisture to dry air or deliver medicated mist. Manufacturers promote such additional features on the packaging and in product descriptions. The overall humidification might not reach the level of a dedicated humidifier, but it can provide some benefit without the need for hot water or a second appliance.


Q. I want to try aromatherapy at home. How do I decide which essential oils to use?

A. Aromatherapy uses different fragrances to elevate the user's mood, increase energy levels, improve mental focus, and other desired results. A professional aromatherapist can recommend specific essential oil blends. Most essential oil manufacturers also include basic information on the packaging, so reading the label could be useful. There are also aromatherapy reference guides and articles available online that explain the beneficial qualities of various essential oils.

Q. Will an essential oil diffuser leave an unpleasant oily residue after use?

A. Generally speaking, the microscopic droplets of water and oil created by an ultrasonic diffuser should evaporate in the air shortly after they are dispersed. However, some models might generate a small amount of oily residue, especially if used for long periods. Position the diffuser away from walls, mirrors, plants, or other places where oil might collect over time.

Q. Can essential oils trigger an allergic reaction? I'm allergic to certain flowers and perfumes.

A. Most essential oil blends are derived from parts of the plant not generally known for triggering allergic reactions, but some people could still be sensitive to the fragrance. Skin contact with some organic essential oils could trigger a reaction, but these situations are rare. Some people are more sensitive to a heavier concentration of fragrance, such as perfumes, not the actual fragrance itself.

Essential oil diffusers we recommend

Best of the best: ZAQ Dew Essential Oil Diffuser

Our take: Works well as part of a larger aromatherapy regimen or as a discreet office/home air freshener.

What we like: Uses ultrasonic waves to generate cold mist, no heating elements. Pastel-colored LED lights create a calming effect. Modern teardrop design.

What we dislike: The water reservoir has a relatively low capacity, requiring several refills throughout the day.

Best bang for your buck: BriteLeafs 2-in-1 Ultrasonic Aroma Diffuser Ultrasonic Humidifier

Our take: Works best as a personal aromatherapy delivery system for a smaller area. Looks attractive on the table.

What we like: Super quiet ultrasonic mist generator. Special lavender oil included in original package. Very appealing price point.

What we dislike: Promoted as a humidifier, but it only generates enough mist for essential oil diffusing. Limited tank capacity.

Choice 3: GreenAir SpaVapor+ Instant Wellness Essential Oil Diffuser

Our take: Ideal for those seeking a straightforward, unobtrusive essential oil delivery system in a bedroom, bathroom, or waiting room.

What we like: Attractive entry-level price point. Six LED color options. Ceramic discs resist oil corrosion. Creates a micro-fine ultrasonic cold mist.

What we dislike: Base unit doesn't include a timer option. More of a clinical aesthetic than decorative.

Michael Pollick is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money. BestReviews never accepts free products from manufacturers and purchases every product it reviews with its own funds.

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