Best Ultrasonic Diffusers That Won’t Break the Bank

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purple image of diffuser and essential oils with text overlay: the 6 best ultrasonic diffusers on a budgetLet’s face it, diffusers can be really expensive, making the best ones out of reach for many of us. Aromatherapy diffusers can be as inexpensive as a few dollars and top the charts at up to $400.00. The top priced diffusers have bells and whistles like mp3 connections and high end material. So, what about for those of us on a budget?

Looking for an ultrasonic diffuser has become more confusing than ever. I counted over 50 brands on Amazon and quite frankly I don’t recognize 90% of them–and I have been writing about diffusers for quite a while now. The silver lining for us as consumers though is that extreme competition has driven the price of ultrasonics lower than ever before. It is now very possible to get a basic ultrasonic, maybe even with a frill or two for less than lunch for two. This guide explains the features in budget diffusers and my top picks.

What features to look for in a budget diffuser

Auto-Shut off and Timers

Most budget diffusers will be pretty basic. Almost all have a safety feature where the diffuser will turn off automatically when the water runs dry.  A lot more budget diffusers now include an intermittent misting setting (something previously only found on more expensive models).

A timer controls how long the unit stays on (separate from auto-shut off when it runs out of water).  The difference between a timer and intermittent mist is the timer will automatically shut off the diffuser after a period of time whereas an intermittent setting just cycles through periods of mist and no mist until you turn it off.

My favorite feature to look for is intermittent misting, and the more flexibility between cycles, the better. Ultrasonic diffusers should only be run for 30 minutes at a time. If you want to run it longer, having it cycle off and on can increase the length of time you can run it. 

Now, your nose and body need a break, so I do recommend giving yourself several hours of fresh air a day. Yet, an intermittent cycle can be helpful for those wanting to run their diffusers for longer periods without overdoing it.

Coverage and Output

The other important feature to consider is room coverage.  Budget ultrasonics are likely to cover the space of a typical room and not much more.

There are two main factors in room coverage: capacity and output level. The capacity is determined by the water reservoir size. Most smaller units hold 1/2 cup (125 ml) , give or take, of water and about 5 drops of essential oils.  

Output level is how strongly a diffuser puts out mist. This is usually  something that cannot be controlled on a simple unit. For output control, the Asasuki has a low or high mist option, or look to the pricier H2E0.

What this means to you is that the level of output will affect the size of room that can be covered. In other words—how forcefully the mist is propelled into the air affects how far it will travel. Meanwhile,  output + water capacity will correspond to continuous run time. In other words, how strongly it mists and how much water is in the tank will determine how long it can run before it is empty. This is why we see some variation between models in their run time despite having a similar sized water tank.

As you can see when you compare models in the table below, most smaller units cover around 200-300 sq. ft. of space and run for a few hours.


So, in a budget model expect to find smaller reservoirs, smaller coverage areas, and run times around 4 hours. My top choice, the Asasuki, gives the most bang for your buck and competes with more expensive models, without the price tag.

Here’s a quick comparison of my top choices.

Model Water Tank Lights Timer or
Run Time Area
Innogear 100 ml Yes, 7 colors 30 sec on/off 4-5 hrs 200 sq. ft.
Asasuki 500 ml Yes, 7 colors 1,2,3 hrs or continuous on Up to 16 hours 270-320 sq. ft.
URPower Wood Grain 150 ml Yes, 7 colors 30 sec on/off or steady on 4 hours 215 sq.ft.
Vic Tsing Mini Wood 150 ml Yes, 6 colors No 5-6 hrs. 250 sq. ft.
150 ml Yes, 6 colors No 5 hrs. 250 sq. ft.
ZAQ Allay 80 ml Yes (plain); diffuser comes in different colors No 4 hrs. 200-300 sq. ft.

My Top Choice for 2019:

The Asasuki is at the top end of our budget range, but the extra few dollars are worth it. With a 500 ml water reservoir and a timer setting, these are two features usually reserved for higher end models. Another unique feature is the ability to choose between high and low mist settings. This is one of the few budget models with this feature. The only thing it is missing is the intermittent misting option. If the company added that, it would have everything! The ability to choose a lower output level along with a 1 hour setting compensates for this one downside.


Runner Up:

URPower Wood Grain: This is a nice looking diffuser for the money. It comes in 2 color choices of faux wood grain and has a vase like shape. The lights are unobtrusive, just glowing from the top spout and around the button. It also features an intermittent misting option of 30 seconds on and 30 seconds off.

The most budget friendly:

Innogear Aromatherapy Diffuser: You can’t really ignore this one as it has amassed thousands of mostly positive reviews on Amazon. This unit has the option for intermittent misting (30 seconds on and off), and the 7 colored lights can be turned off. It’s not beautiful, but the price is right and it works. An alternative is the URPower, which is nearly identical.

Compact with a Timer:

The Vic Tsing mini (150 ml) diffuser is a compact diffuser available in three different faux woodgrain finishes. Vic Tsing makes several similar looking diffusers varying slightly in shape and water capacity. Some of the larger ones have intermittent mist features. The mini does not, but does have  a 1 or 3 hour timer.

The old kids on the block:

One thing I look for in a diffuser is a company that is focused on aromatherapy products, not just jumping on the diffuser bandwagon for a quick buck.  Green Air and ZAQ have been producing diffusers longer than some of the other companies in this list. They are not the cheapest or most feature rich, but they have stood the test of time.

GreenAir SpaVapor+: This is another popular budget diffuser, is widely available from several online retailers, and has been around for longer than a lot of the other diffusers listed here. It has 6 LED color changing lights, which can be turned off. It also has a directional spout so you can focus your mist in different directions. There is a newer version—the 2.0 which adds a timer feature and a short intermittent setting. Sometimes the 2.0 is on sale for just a few dollars more than the more basic SpaVapor+, which can make it a good deal.

ZAQ Allay: ZAQ makes a whole line of ultrasonic diffusers in a variety of interesting shapes. The vase like Allay is one of the more popular models. It has a single light color (the diffuser comes in your choice of 3 colors), an 80 ml reservoir, and will run for up to 4 hours. This is another model that is often on sale in the budget range, but retails for more.

Whichever model you choose, proper maintenance can help keeping it running smoothly. Empty the water out at the end of the day and wipe it out with a soft cloth once a week. If something does go wrong, most of the models I have listed here have a 1 year limited warranty.

Further Reading: Choosing a Diffuser–the Ultimate Guide

Originally published November 26, 2014, fully updated January 14, 2019

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