Coway Airmega 400 Air Purifier
Where to Buy
| Retailer | Price | Last seen | Buy |
|---|---|---|---|
 Walmart 90-day returns (in store too) | $161.00 | Mar 9, 2026, may have changed | Buy Now |
S Soxy | $259.60 | Sep 19, 2022, may have changed | Buy Now |
S Sarimnor | $340.09 | Dec 21, 2022, may have changed | Buy Now |
 Amazon 30-day returns (in store too) | $441.74 | Mar 9, 2026, may have changed | Buy Now |
S Shopping.com | $464.99 | Jul 4, 2022, may have changed | Buy Now |
Prices are collected from retailer listings; each row shows the date we last saw that price. Return and shipping terms are each store's standard policy from our retailer research (April 2026). Some products and categories have different terms, so check with the store before you buy.
Used & Refurbished
✨ See 1 used & refurbished price with ShopSavvy ProGet the app →Price history summary
Lowest new price we recorded at major retailers (Amazon, Walmart, Best Buy, Target, The Home Depot and Lowes) in the last 90 days: $369.49 at Amazon on Sep 29, 2026.
Range over the last 12 months: $161.00 (Walmart, Mar 9, 2026) to $519.20 (retailers/amazon, Dec 3, 2025). Based on 39 recorded prices since Oct 26, 2025 for offers sold by these retailers themselves (not marketplace sellers). Summary as of Oct 14, 2026.
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Pros
- •Significantly reduces allergy symptoms, including reactions to dust, grass, and pollen, improving overall respiratory comfort.
- •Effectively cleans large spaces up to 1,560 sq. ft., including rooms with high ceilings and poor ventilation.
- •Smart technology with automatic fan speed adjustment responds to changes in air quality and can be scheduled via an intuitive app with simple WiFi setup.
- •Very quiet operation, especially at low and medium fan speeds, suitable for overnight use without disturbance.
- •Noticeably reduces dust accumulation on furniture and improves removal of cooking and food odors quickly.
- •Sleek, modern, and minimalistic design fits well in any room décor.
- •Filter indicators for cleaning and replacement make maintenance straightforward.
- •Backed by a 5-year warranty, offering some peace of mind (though see cons).
- •Outperforms some comparable models like Winix in efficiency and smart features.
Cons
- •The filters emit a strong, unpleasant chemical odor that fills indoor spaces, which is a persistent issue acknowledged but unaddressed by the manufacturer.
- •Many users rely on fragrances to mask the odor rather than fixing the root problem, and replacement or cloned filters often share this same issue.
- •Air quality sensor and automatic fan speed adjustment tend to malfunction after about a year, causing the purifier to stay permanently on low speed and miss poor air quality events.
- •The sensor test method used for warranty validation is unrealistic and does not reflect typical user experience, leading to frustration and difficulties in warranty claims.
- •Filter lifespan is shorter than advertised, requiring replacements approximately every 8 months, which makes the high filter replacement cost ($129) less economical.
- •Pre-filters require frequent cleaning, about every couple of weeks, even in areas with low dust.
- •Although generally quiet, the highest fan speed can be noticeably loud.
- •The 5-year warranty offers limited protection on sensor failures and other technical issues, disappointing some customers.
Bottom Line
The Coway Airmega 400 Smart Air Purifier is a powerful, quiet option that excels at clearing large spaces and reducing allergy symptoms with smart features and easy app control—*if you can tolerate that lingering chemical filter smell*. However, its recurring filter odor issue and the sensor’s eventual unreliability are significant drawbacks, especially given the high cost of filter replacements and less-than-ideal warranty support. If sensor reliability and odor-free filtration are critical, you might want to explore alternative models or brands. Still, for those prioritizing coverage area and smart tech in a sleek package, this unit delivers solid performance.
What Reviewers Are Saying
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Discussion
ShopSavvy compares prices across thousands of retailers so you always get the best deal. Prices are collected from retailer listings, and each one shows the date we last saw it. Our expert reviews and community discussion help you make informed buying decisions.