Paku – Air Quality & AQI Map is a free iPhone app that puts live readings from public PurpleAir and AirGradient sensors, plus official AirNow stations, on one map. It holds 4.7 stars from 10,991 App Store ratings, and the listing says the map and widgets are free while alerts, Live Activities and private sensors need Paku Pro.
Quick verdict
If wildfire smoke changes your plans, Paku is worth a look. Many reviewers use it during smoke or fire season, and many call it easy to use. Several like seeing readings for their own neighborhood or block, and several PurpleAir owners like it for checking their own sensor. The main complaint is the numbers themselves: several reviewers say readings were off, and in a few of those reviews the app showed good air while smoke covered their area. A few reviewers also say there’s no working sensor near where they live.
Paku at a glance
| Developer | Pitou Technologies, LLC |
|---|---|
| Store listing | Paku – Air Quality & AQI Map on the App Store |
| Price | Free. The listing names Paku Pro, “a small subscription or one-time lifetime unlock”; our data doesn’t include its price. |
| Ads | Not stated in the listing. A few reviewers say it has no ads. |
| App Store rating | 4.7 stars from 10,991 ratings |
| Downloads | Not in our data |
| Version / last updated | 7.5.2 / November 11, 2026 |
| Requires | iOS 26.0 or later |
| First released | October 2, 2020 |
| Data checked | November 12, 2026 |
What is Paku?
Paku is an air quality map built on community sensors. The listing says it shows live readings from thousands of PurpleAir and AirGradient sensors, indoors and out, with AQI, temperature, humidity and trends, and that official AirNow government stations are on the map too. It runs on iPhone, iPad, Apple Watch and Mac. The listing also says it’s made by one person.
Key features
- Sensor map: every public PurpleAir and AirGradient sensor, indoors and outdoors, with AQI, temperature, humidity and how readings are trending. AirNow government stations appear too, and a Data Sources screen lets you pick which networks you see.
- Smart Select: the listing says it picks the most reliable sensor near you, “not just the closest one.”
- Widgets: the nearest sensor, a favorite spot or your own sensor on the Home Screen, Lock Screen, Apple Watch or Mac desktop.
- Alerts (Pro): set a threshold on any sensor and get a notification when it’s crossed and again when the air clears. Nearby alerts can follow the closest sensor as you move, on your device.
- Live Activities (Pro): AQI and its trend in the Dynamic Island or on the Lock Screen.
- Your own sensors (Pro): add private PurpleAir sensors and use them on the map, in widgets and with alerts.
- Siri, Spotlight and Shortcuts: ask Siri for nearby air quality, check it from Spotlight, or use the AQI in automations, such as turning on an air purifier.
- Sync: favorites and settings sync over iCloud across iPhone, iPad, Apple Watch and Mac, with a live reading in your menu bar.
Paku vs. what a weather app should have
We file Paku under weather, so it’s scored against our weather checklist, though it only covers air quality plus sensor temperature and humidity. “Listed” means the App Store listing names the feature, “Partial” means it covers part of it, and “Not listed” means the listing doesn’t mention it. Forecasts, radar and rain aren’t part of what the listing describes.
Must have
| Feature | Status | Notes |
|---|---|---|
| Current conditions and feels-like | Partial | Sensor temperature and humidity are listed; feels-like isn’t |
| Hourly forecast | Not listed | |
| Daily forecast of 7+ days | Not listed | |
| Chance of precipitation | Not listed | |
| Wind, humidity, UV index | Partial | Humidity is listed; wind and UV index aren’t |
| Severe weather alerts | Not listed | Threshold alerts on sensors (Pro); no weather alerts are listed |
| Radar map | Not listed | The map shows air sensors |
| Home-screen widgets | Listed | Home Screen, Lock Screen, Apple Watch and Mac desktop |
| Current location and search | Partial | Nearest sensor and favorites are listed; search isn’t |
| Unit options (°F/°C) | Not listed |
Should have
| Feature | Status | Notes |
|---|---|---|
| Notification or lock-screen weather | Partial | Lock Screen widgets and Live Activities show AQI; weather isn’t named |
| Air quality | Listed | The app’s main purpose |
| Multiple saved locations | Listed | Favorites, synced over iCloud |
| Choice of data source | Listed | A Data Sources screen lets you choose which networks you see |
| Layout customization | Not listed | |
| Light and dark themes | Not listed | |
| Sunrise, sunset, moon phase | Not listed | |
| Multiple languages | Not listed |
Nice to have
| Feature | Status | Notes |
|---|---|---|
| Animated wind or global map | Not listed | |
| Side-by-side provider comparison | Not listed | |
| Photography times (golden/blue hour) | Not listed | |
| Weather photos | Not listed | |
| Pollen | Not listed | One reviewer uses PM10 readings from a nearby sensor to track their allergy season |
| Lightning strike information | Not listed | |
| Custom temperature alerts | Not listed | |
| Rain-incoming notifications | Not listed | |
| Written forecast summary | Not listed |
Paku does one thing: current air quality from nearby sensors. For a forecast, radar or rain alerts you’ll need a second app.
Common problems reviewers report
The data we collected doesn’t include developer replies, so this table lists what reviewers report and when. Newer versions may behave differently.
| Problem | What reviewers report | When |
|---|---|---|
| Good air shown during smoke | One reviewer says the app showed an AQI of 10 while smoke from the Woodside Fire covered Sonoma County, and later learned the local AQI had reached 197. Another says it showed good air quality while thick smoke covered their neighborhood. A third says the dot near their town showed green at 20 while the text said 158. | August 2024 to July 2026 |
| Readings differ from PurpleAir or other sources | A few reviewers compare Paku with other sources: one owner says it reads their sensor 15 to 25 points lower than their own reading, two say it reads low compared with PurpleAir, and two others say it reads far higher than other sites. | August 2021 to August 2023 |
| New PurpleAir sensor missing from the map | A few owners say their sensor appeared on the PurpleAir website but not in Paku. | August 2021 to September 2022 |
| Widgets stop working or won’t add | One reviewer says a few restarts got the widgets working again; another managed to add widgets after a reboot. | November 2024 |
| Stuck in the oval at the top of the screen | One reviewer says the app appears in the oval at the top of the iPhone and nothing turns it off. | August 2026 |
| Repeated rating prompts | Two reviewers say the app keeps asking them to rate it. | February and August 2026 |
Don’t rely on a single app for severe weather or smoke warnings. Check official alerts from your local authorities too.
Pros (from user reviews)
- Wildfire smoke: many reviewers use Paku during wildfire smoke or fire season. A few others say it showed good air while smoke was thick (see Cons).
- Easy to use: many reviewers call it easy, simple or intuitive. Several say it’s easier than the PurpleAir website.
- Local readings: seeing the air on your own street or block is what several reviewers like. One sees a sensor less than a mile away; another gets readings within a quarter mile of the house.
- Planning the day: for several reviewers, the reading decides whether they exercise outside, open the windows, wear a mask or let the kids out.
- Accuracy: several reviewers call the readings accurate, and a few say it’s more useful or accurate than their phone’s weather app or national weather apps. Several others disagree (see Cons).
- Health: people with asthma, allergies, impaired lungs or other conditions make up several of the reviewers who rely on it.
- Widgets and Apple Watch: several reviewers praise the widgets, including on the Lock Screen, and a few mention the Apple Watch.
- PurpleAir owners: several reviewers who own a PurpleAir sensor say Paku is a good way to check it.
- Developer and support: several reviewers say the developer or support responded to them, and one says a freezing problem they reported was fixed in later updates.
- Design and speed: the design gets praise from several reviewers, and several call the app fast or responsive.
- Alerts: a few reviewers like the alerts that tell them when the AQI gets worse or improves.
- Price: a few reviewers say the subscription is worth it or fairly priced, and a few say it has no ads.
Cons (from user reviews)
- Readings that seem off: several reviewers say the numbers were wrong. In a few reviews the app showed good air during heavy smoke; others say Paku read lower or higher than PurpleAir or other sources. One reviewer using it at a mine job site says people looking at the same sensor saw numbers that differed “by sometimes hundreds of points.”
- Widget trouble: several reviewers say widgets stopped updating, ignored their settings or couldn’t be added.
- Paid features: a few reviewers object to the paid tier. One, in 2024, says widgets became available only to paid subscribers; another, in 2023, says showing their own sensor on a widget was locked behind a paywall. The current listing says the widgets are free, while private sensors are part of Pro.
- No sensor nearby: a few reviewers say there’s no working sensor near where they live. Two want better coverage outside the US and parts of Europe, and both mention ambee as a possible source.
- Map colors: a few reviewers complain about the map colors or heat map, and one says the new dense heat map makes city names hard to read.
- Crashes and errors: a few reviewers report crashes or connection errors. One says the app crashed or showed the wrong map location after updating to iOS 26.
- Contacting support: two reviewers say they couldn’t reach support or the developer; one didn’t want to join Mastodon to do it.
The data we collected doesn’t include a star breakdown of the 10,991 ratings. The newest review in our data is from November 2026.
Pricing
Paku is free on the App Store. The listing says “the map, the widgets, and the rest are free,” and that alerts, Live Activities and private sensors are part of Paku Pro, “a small subscription or one-time lifetime unlock.” Our data doesn’t include the Pro price. If you mainly want to glance at the map or a widget, the free tier covers it; if you want a notification when the air turns bad, you’ll need Pro.
Privacy and permissions
We couldn’t read the App Store privacy label, and our data doesn’t include a permissions list. The listing says “Your location never leaves your device. No account, no tracking, no data collection,” and that nearby alerts work entirely on your device. One reviewer says it “doesn’t collect data on me.” Another, in 2023, complained that the app asks for location and has no way to set a default location.
Who it’s for
Paku suits you if you live where wildfire smoke or pollution comes and goes and you want to see the sensor nearest your home, not a city-wide number. It’s a good match if you own a PurpleAir sensor, or if you have asthma or allergies and check the air before going out. Skip it if you want a full weather app with forecasts and radar, or if you live somewhere with few public sensors: check the map for sensors near you first. On smoky days, compare its reading with another source before you open the windows.
FAQ
Is Paku free?
Yes. The listing says the map, the widgets and the rest are free. Alerts, Live Activities and private sensors are part of Paku Pro, which the listing describes as a small subscription or a one-time lifetime unlock.
Does Paku work with my own PurpleAir sensor?
Yes. The listing says you can add private PurpleAir sensors and use them on the map, in widgets and with alerts, as part of Paku Pro. Several reviewers who own a PurpleAir sensor say Paku is a good way to check it, though a few say a newly installed sensor didn’t show up on the map.
Is Paku accurate during wildfire smoke?
Reviewers disagree. Several call the readings accurate, and many use the app during smoke season. A few others say it showed good air while smoke was thick, including one who saw an AQI of 10 while the local AQI had reached 197.
Does Paku work outside the US?
The listing doesn’t list countries. One reviewer uses it in Mexico City with their own PurpleAir sensor. Two others want better coverage outside the US and parts of Europe, and one names the Middle East, Africa and much of Asia.
How this review was put together
We haven’t tested Paku. This review is based on public information from official sources: the app’s Google Play or App Store listing and rating breakdown, the developer’s website when there is one, and recent user reviews on the store with the developer’s replies. Features and claims are the developer’s own descriptions; what users like and dislike comes from the store reviews. Everything was checked on November 12, 2026. Apps change with every update, so check the store listing before you install.
