Softwr

Weather · head to head

EPA AirNow vs PurpleAir

EPA AirNow logo

EPA AirNow

Weather

Official U.S. government air quality information

From
Free
Rated
-
Full reviewWebsite
PurpleAir logo

PurpleAir

Weather

Real-time air quality monitoring for communities

From
$229/one-time
Rated
-
Full reviewWebsite

The short version

  • Only EPA AirNow has a free tier, so it costs nothing to try first.
  • Each has a real cost: EPA AirNow air quality data availability depends on nearby monitoring stations, can show no data found near a location when no monitor is close enough; PurpleAir purpleAir sensors are one-time hardware purchases rather than a subscription, priced $199 to $279 USD per unit for named models (PA-I-Indoor, PA-II, PA-II-SD), per the vendor's own store (archived, 2021).
  • They diverge on capability: EPA AirNow covers Official AQI data, PurpleAir covers PM2.5 monitoring.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which EPA AirNow and PurpleAir actually diverge.

Attributes where EPA AirNow and PurpleAir differ
AttributeEPA AirNowPurpleAir
Starting priceFree$229/one-time
Pricing modelfreeone-time
Free tierYesNo
PlatformsiOS, Android, WebWeb, Api, Hardware
Founded19702015

Identical on both: user rating (Not yet rated), category (Weather).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in EPA AirNow

  • Official AQI data
  • Air quality forecasts
  • Fire & smoke data
  • Health recommendations
  • Data feeds
  • Widgets
  • API

Only in PurpleAir

  • PM2.5 monitoring
  • Real-time map
  • Historical data
  • Community network
  • Home Assistant
  • Data downloads
  • Hardware support

Both cover

  • API access
  • Web support
  • Api support

What people use each for

The jobs each tool is most often brought in to do.

EPA AirNow

  • Checking current Air Quality Index (AQI) for a location or any searched areanot PurpleAir
  • Viewing next-day AQI forecasts to plan outdoor activitiesnot PurpleAir
  • Monitoring wildfire smoke via the Fire and Smoke Map (built with the U.S. Forest Service)not PurpleAir
  • Saving multiple locations for quick referencenot PurpleAir
  • Receiving optional push notifications for local AQI forecastsnot PurpleAir

PurpleAir

  • Professional Worknot EPA AirNow
  • Content Creationnot EPA AirNow

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

EPA AirNow

  • Air quality data availability depends on nearby monitoring stations, can show no data found near a location when no monitor is close enough
  • Interactive monitor map (PM2.5, PM10, ozone) coverage documented on the primary source is U.S.-focused
  • As a government-run service it offers no paid tiers, proprietary data sources, or customization options found in commercial weather/air-quality apps

PurpleAir

  • PurpleAir sensors are one-time hardware purchases rather than a subscription, priced $199 to $279 USD per unit for named models (PA-I-Indoor, PA-II, PA-II-SD), per the vendor's own store (archived, 2021).

Pricing, plan by plan

EPA AirNow

Free

No published plan breakdown. See the EPA AirNow review.

PurpleAir

$229/one-time
  • Outdoor Sensor$229/one-time
    • PM2.5 monitoring
    • Cloud connectivity
    • Map access
  • Indoor Sensor$199/one-time
    • Indoor monitoring
    • WiFi enabled
    • Real-time data

Which should you pick?

Choose EPA AirNow if

  • You need official aqi data.
  • You want to start without paying.
  • You work on iOS, Android, Web.
  • You also want air quality forecasts.
EPA AirNow review

Choose PurpleAir if

  • You need pm2.5 monitoring.
  • You work on Web, Api, Hardware.
  • You also want real-time map.
PurpleAir review

Questions people ask

Is EPA AirNow or PurpleAir better?
Neither clearly leads. EPA AirNow starts at Free and PurpleAir at $229/one-time, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, EPA AirNow or PurpleAir?
EPA AirNow has a free tier; the other does not. Paid plans start at Free for EPA AirNow and $229/one-time for PurpleAir.
Does EPA AirNow or PurpleAir run on more platforms?
EPA AirNow runs on iOS, Android, Web. PurpleAir runs on Web, Api, Hardware.
Can I use EPA AirNow for free?
Yes. EPA AirNow has a free tier, so you can try it without paying. PurpleAir starts at $229/one-time.
What is EPA AirNow best used for?
EPA AirNow is most often used for checking current air quality index (aqi) for a location or any searched area, viewing next-day aqi forecasts to plan outdoor activities, monitoring wildfire smoke via the fire and smoke map (built with the u.s. forest service), saving multiple locations for quick reference. Of those, checking current air quality index (aqi) for a location or any searched area and viewing next-day aqi forecasts to plan outdoor activities are not what PurpleAir is typically brought in for.
What can EPA AirNow do that PurpleAir cannot?
EPA AirNow covers Official AQI data, Air quality forecasts, Fire & smoke data, Health recommendations. PurpleAir covers PM2.5 monitoring, Real-time map, Historical data, Community network. Both handle API access, Web support, Api support.

Answered from the vendors’ own pages

EPA AirNow: Is AirNow.gov free to use?

Yes. AirNow.gov is a free service operated by the EPA and its partners that provides air quality data, forecasts, maps, and educational resources at no cost to users.

Source
EPA AirNow: Are there any subscription costs or fees associated with AirNow.gov?

No. AirNow.gov offers all services, data access, and tools completely free. There are no subscription tiers, fees, or payment options of any kind.

Source
Share

Related pages

More on EPA AirNow

More on PurpleAir

Keep looking

Other head to heads