The best air purifier for 2025

To help inform our air purifier picks, we gathered 14 of the most popular models at CNET Labs’ product testing facility in Louisville, Kentucky, where we put them through a rigorous set of tests. Our goal was to determine which air purifiers offer the best performance in terms of particle removal efficiency, energy consumption, and quietness, while evaluating their respective feature sets and value.

The particle removal test

The air we breathe is not just air. It is actually a combination of man-made and naturally occurring particles. The former is composed primarily of urban, industrial, and vehicular emissions of hydrocarbons, nitrogen oxides, and combustion byproducts, and the latter is primarily represented by forest fire smoke, sulfates, soot, and matter from volcanic activity worldwide.

According to EPAsome of these microscopic solids and liquid droplets, which can be made up of hundreds of different chemicals, are so small that it’s almost unavoidable to inhale them. PM10 and PM2.5, which are particles with a diameter of less than 10 and 2.5 micrometers, respectively, pose the greatest risk to human health after inhalation. They are distributed deep into the lungs and even into the bloodstream, disrupting the proper functionality of the lungs and heart.

“This is the size that can go into our body, into our lungs and into our blood,” Zhao said. “It’s the number one environmental factor globally. It kills about 6 to 7 million people a year,” he said, due to cardiovascular or respiratory problems caused by particulate pollutants.

Our custom air cleaner test chamber uses a clear front panel made of Plexiglas and gloved hand access that allows us to manipulate the air cleaners, a particle counter holder for our control device, two fans that ensure proper mixing air and smoke inside the chamber, vents to ensure a small amount of fresh air is available at all times, an ignition port to ignite the smoke bombs outside the platform and an exhaust vent that safely removes residual smoke from the chamber and building after each test.

The chamber is not hermetically sealed, but it is tight enough to ensure that no dangerous amount of smoke escapes. Our mission was to create an environment where we exposed each air purifier to air saturated with particles of approximately the same concentration to assess how quickly and efficiently they returned the air to breathable conditions.

We made custom smoke bombs that are made of 50% potassium nitrate (KNO3), 40% sucrose (sugar) and 10% sodium bicarbonate (baking soda) and included a safety fuse for remote ignition. The sugar acts as a fuel source while the potassium nitrate acts as an oxidizer and the baking soda ensures that our dry mix maintains a slow and even burn.

Using the Temtop PMD331 particle counter, we were able to verify that 5 grams of our dry smoke bomb mix produced approximately between 590 million and 610 million particles per cubic meter. The device can count particles of different sizes, including PM2.5 and PM10, and records this data once every 15 seconds. Although we can count particles of different sizes individually, the total number of particles we are interested in is the sum of all particles of different sizes.

We prepared a 5 gram smoke bomb that ignites through the ignition port after installing the air cleaner and ensuring proper sealing. Once the air in the chamber becomes saturated with particles (more than 580 million particles/m3), we turn on the air purifier in question. The data retrieved from Temtop allows us to accurately track the impact the air purifier has on particle counts in real time.

Noise level

Using a decibel meter, we measured how noisy the air cleaners were at their low, medium, and high fan settings. This is especially important if you plan to put the air purifier in your bedroom at night and don’t want it to disturb your sleep. We performed this test in our sound enhancement studio to ensure that the decibel meter only picks up sound waves from the air cleaners, excluding other possible sources.

Energy consumption

To answer this question, we used a device called Kill-a-Watt and measures how much energy each air purifier consumes at different fan settings. Knowing the energy consumption of your air purifier can make a difference in your energy bill.