> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sonohealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Air Purifier vs Humidifier vs Dehumidifier: What's the Difference?

> Air purifiers, humidifiers, and dehumidifiers do completely different jobs. A clear comparison to help you pick the right device — or know when you need more than one.

These three devices are often confused, but they solve different problems. Picking the wrong one is a common and costly mistake. Here's how they differ and when you might want each.

## What does an air purifier do?

An air purifier **cleans** the air by removing particles and many odors. A unit like the [AirPro](/air-purifier/overview) uses [HEPA 14 filtration](/air-purifier/hepa-14-filtration) to capture dust, pollen, dander, mold spores, and smoke, plus activated carbon for odors and VOCs. It does not change humidity at all — it neither adds nor removes moisture.

## What does a humidifier do?

A humidifier **adds moisture** to dry air, which can ease dry skin, scratchy throats, and irritation common in winter or arid climates. It does not clean the air or remove allergens, and if overused or poorly maintained it can actually raise humidity enough to encourage mold and dust mites.

## What does a dehumidifier do?

A dehumidifier **removes moisture** from damp air, helping prevent mold, musty smells, and dust-mite growth in humid spaces like basements. Like a humidifier, it does not filter particles or odors from the air.

## Which one do I actually need?

| Problem                                | Right device |
| -------------------------------------- | ------------ |
| Dust, pollen, dander, smoke, odors     | Air purifier |
| Dry air, dry skin, winter congestion   | Humidifier   |
| Dampness, musty smell, mold-prone room | Dehumidifier |

Many homes benefit from more than one. For example, a damp, allergy-prone basement might use both a dehumidifier (to control moisture) and an air purifier (to capture spores and dust) — see [mold protection](/air-purifier/mold-protection).

## Does an air purifier dry out the air?

No. Because it only moves air through filters, the AirPro does not remove moisture or dry out a room the way an AC or dehumidifier does. If your air feels dry, that's a job for a humidifier, not a purifier.

<Note>
  An air purifier and a humidifier solve opposite-feeling problems and can be used together, but neither replaces the other. In damp or mold-prone spaces, address the moisture source first; a purifier helps capture airborne spores but won't fix humidity.
</Note>

**Related:** [Mold Protection](/air-purifier/mold-protection) · [Air Quality Guide](/air-purifier/air-quality-guide) · [Do Air Purifiers Work?](/air-purifier/do-air-purifiers-work)