aqi.ninja

What It Is

AQI.ninja is a minimalist air-quality information service: users enter a PurpleAir sensor ID in the URL to get an AQI value calculated using the US EPA correction. It is not a full-fledged air-quality platform; it is more of a lightweight lookup and sharing tool designed to let users quickly check air quality at one or more fixed locations without repeatedly zooming and panning around the PurpleAir map.

Core Features and Developer-Friendliness

In terms of functionality, it supports querying a single sensor, as well as listing multiple sensors at once with commas. You can also add :name to give a sensor a more familiar display name, which is useful for creating bookmarks for family members or non-technical users. One developer-friendly detail is that URLs can be appended with .json or .txt: .txt is especially suitable for command-line use with tools like curl, while .json can be used for simple scripts or dashboard integrations. The page also notes that you can build URLs by clicking sensors on the AQI.ninja map. Cloudflare’s approximate geolocation is used to center the map, and cookies are used.

Pricing, Openness, and Ecosystem

The main content does not disclose pricing or payment methods, nor does it state whether the service is open source or supports self-hosting. There is no official SDK for APIs/SDKs; access is mainly through URL routes. Ecosystem integrations are currently very limited. The service primarily relies on PurpleAir sensor data and uses the US EPA correction for calculations. Because data is cached for several minutes, results may not exactly match the real-time display on the PurpleAir website.

Pros, Cons, and Best-Fit Users

Its strengths are that it is simple, shareable, bookmarkable, and scriptable. It is suitable for outdoor users comparing smoke conditions across multiple locations, and also for creating fixed lookup links for parents or grandparents. The drawbacks are also clear: the author explicitly describes it as “very experimental” and “still in progress,” and its current functionality is limited to AQI lookup. The documentation consists only of examples and an FAQ, with no details on error codes, rate limits, stability, versioning, or service commitments. As a result, it is not suitable as the sole data source for mission-critical systems.

Access from China and Alternatives

The page does not provide information about access from mainland China, network connectivity, or payment options. Since the service is hosted on Cloudflare, real-world availability needs to be tested; for now, it should be considered unknown. If you need a more mature data source or a global air-quality platform, alternatives worth considering include PurpleAir, AirNow, WAQI, IQAir, and OpenAQ.