Canairy blog
Air quality apps compared, including ours
Canairy · 9 min read · 2026-08-12
We make one of these. You should read this knowing that, and the goal here is still to help you pick the right one even when that isn't Canairy — partly because a comparison written to make us look good would be obvious and useless, and partly because these apps genuinely suit different people.
What this is: a comparison of platforms, prices, data sources and alerting, taken from each vendor's own store listing and documentation, verified on 12 August 2026. Prices and features change; the date matters.
What this isn't: a hands-on review. We have not lived with each of these apps for a month, and we are not going to pretend otherwise by describing how they feel to use. Where we say something is missing, it is missing from what the vendor publishes.
While checking, we found that three claims circulating in other comparisons are simply wrong. They are corrected below.
The comparison
| App | Platforms | Price | Data source | Proactive alerts | Account |
|---|---|---|---|---|---|
| EPA AirNow | iOS, Android | Free, no in-app purchases | Government reference monitors; Fire and Smoke Map adds low-cost sensors | Yes — "Forecast Notifications", advertised on iOS | None indicated |
| IQAir AirVisual | iOS, Android, watchOS | Free, no in-app purchases on either store listing | Government stations plus IQAir's own monitor network | Yes, configurable by time of day or AQI level | Not stated |
| Paku | Apple only (iOS 26+) | Free; Pro is $1.99/mo, $13.99/yr, or $89.99 lifetime | Every public PurpleAir sensor, optional AirNow | Yes — but Pro-gated | None; syncs via iCloud |
| Smog Report | Apple only | Free, tip to remove ads | EPA AirNow, OpenAQ, Singapore NEA — reference monitors only | Yes, on category change | None |
| Apple Weather | Built into iOS/macOS | Free | BreezoMeter (per Apple's own docs) | No — only Severe Weather and Next-Hour Precipitation | Apple Account |
| Canairy | iOS, Android | Free with ads; Plus and Pro are paid | PurpleAir sensors, EPA AirNow fallback, Google Pollen | Yes, per-location thresholds, push and SMS | Required |
Three corrections
- IQAir AirVisual does not cost $4.99/month. Several comparisons say it does. Both the App Store and Google Play listings show the app as free with no in-app purchases disclosed. The confusion looks like the AirVisual Pro, which is IQAir's indoor hardware monitor, not an app tier.
- AirNow's alerts no longer require EnviroFlash. The iOS listing says "Forecast Notifications are now available!" EnviroFlash is a separate EPA and state-agency email or SMS service you subscribe to on the web — useful, but not the app's notification mechanism.
- Paku is not $2.99 one-time. Its actual in-app purchases are a $1.99 monthly subscription, a $13.99 annual, and an $89.99 lifetime unlock.
What each is good at, and what's missing
EPA AirNow — the free official one
Good at: being the source of record. It is the government's own app, free, no account, no ads, no upsell, and its numbers are the legal ones. Multiple saved areas. It covers the US, Canada and Mexico, and the Fire and Smoke Map is the canonical smoke view.
Missing: neighbourhood resolution. Reference monitors are sparse — about a thousand PM2.5 monitors nationally, and most counties have none — so "your area" can mean a monitor twenty miles away. Its real-time number is a NowCast averaged over up to twelve hours, which lags an arriving plume. Notification support is advertised on iOS but not mentioned on the Android listing.
Best for: anyone who wants the official number and nothing else. If that's you, stop here, it's free.
IQAir AirVisual — the widest coverage
Good at: breadth. It claims 500,000+ locations globally, has multi-day forecasts, and its alerts can be set by time of day or by sensitivity level. Free with no disclosed in-app purchases, which for the feature set is notable.
Missing: community sensor density — its crowdsourced layer is IQAir's own monitor network, not PurpleAir's. IQAir also sells air purifiers and monitors, so the app is a funnel; whether that bothers you is a judgement call, not a defect.
Best for: international coverage, and anyone outside the US where AirNow doesn't reach.
Paku — the PurpleAir specialist
Good at: being the best native front-end for PurpleAir, which has no app of its own. Every public sensor, optional AirNow overlay, and a "Smart Select" that picks the most reliable nearby sensor rather than the closest. Location data stays on the device. Widgets and Live Activities are genuinely good.
Missing: Android, entirely — and it requires a very recent iOS. Alerts are behind Pro.
Best for: iPhone owners who want raw PurpleAir depth and will pay for it.
Smog Report — the clean free one
Good at: simplicity and privacy. Free, no account, no tracking, reference monitors from about 100 countries, alerts on category change. Its own guides are good and honest about data provenance.
Missing: Android and web. And by design it uses reference monitors only, no citizen sensors — which is a defensible choice for accuracy and the exact opposite trade-off from Paku or us. Ads unless you tip.
Best for: someone who wants official data, simply presented, on an iPhone, for free.
Apple Weather — already on your phone
Good at: being there. Free, zero setup, and fine for a glance.
Missing: it cannot alert you about air quality at all. Apple's own documentation lists exactly two notification types — Severe Weather and Next-Hour Precipitation. There is no air-quality option. So it can show you bad air, but only if you think to look. Worth knowing that Apple's US air quality still comes from BreezoMeter, which Google acquired and which no longer exists as a consumer product.
Best for: a glance, not a warning.
Canairy — what we're good at, and what we're not
Good at: the alerting case specifically. You add the places that matter — home, a kid's school, a parent's house, a trail — set a threshold per place, and it texts or notifies you when the air crosses it, then tells you when it clears. Quiet hours are respected. Every sensor behind a number is shown with its distance and direction, so you can see when sensors disagree. Pollen is included on every plan, free one included. The app is available in Spanish.
What's missing — genuinely:
- Air quality data is US-only. If you travel, or live anywhere else, one of the others is a better choice.
- An account is required. Every other app here works without one. Ours needs one because the alerting is server-side — we have to know where to send the message — but it is still friction the others don't have.
- The free plan is one location, refreshed every two hours, with ads. On a fast-moving smoke event a two-hour cadence can be up to two hours behind. That's a deliberate difference between plans, and it means the free tier is a weaker product than free AirNow or free Smog Report for pure monitoring.
- No web app. Our website has live city pages, but there is no browser version of the product.
- Our guide articles, emails and website are English-only, even though the app is bilingual.
- PM2.5 is the headline; ozone is not. We surface the EPA forecast's pollutant when ozone is driving the day, but the live number is fine particles.
- We were wrong about the AQI scale until this month. EPA revised the PM2.5 breakpoints in May 2024 and we didn't pick it up until August 2026, so our numbers ran lower than AirNow's for over two years. It's fixed. We're mentioning it because a page like this is worthless if it only lists the flattering facts.
Best for: somebody who is tired of remembering to check, has more than one place to worry about, and wants to be told.
How we picked these, and what we left out
Included: apps a US person could actually install today and use for outdoor air quality.
Left out, and why:
- BreezoMeter — gone as a consumer product. Its own domain now redirects to Google Maps Platform, and its apps return 404 on both stores. The technology lives on as a Google API, which is why Apple Weather still credits it.
- PurpleAir — no native app of its own. Their real-time map is an installable web app, and PurpleAir staff say a native app is a hope rather than a plan. Native access comes via third parties like Paku.
- Plume Labs — still downloadable on both stores, but not updated since May 2022 on iOS and October 2023 on Android. AccuWeather acquired Plume Labs in January 2022 and has published no discontinuation notice, so we won't call it dead — but we won't recommend an app nobody has shipped a fix for in years either.
- Weather apps generally — AccuWeather, Weather.com and others show an AQI. If a number in a weather app is enough for you, you don't need any of these.
If you only remember one thing
Every app on this list except ours is essentially a dashboard: it is accurate, and it waits for you to open it. That's the right tool if you check on purpose. If the problem is that you keep forgetting to check until your throat is already scratchy, what you want is something that watches and interrupts you — and you should judge these apps on their alerting, not their maps.
There's more on how the underlying data actually works in PurpleAir vs AirNow, and on exactly what we run in How Canairy Reads the Air.