M
API Matrix

Purple Air API

Science & Math / No Auth Required Beginner HTTPS
Free to Use Varies (check documentation)
82 Score
Grade A
Visit Official Site Compare Alternatives

Overview

Purple Air gives you access to real-time air quality data from a global network of community-owned sensors. You can query sensor readings, location data, and historical air quality metrics without any authentication. It is a great starting point for environmental monitoring projects or building local air quality dashboards.

💡

Beginner Tip

PurpleAir sensors report PM2.5 particulate matter — query by sensor ID or bounding box to get readings for a specific area. Note that the newer API v1 (api.purpleair.com) now requires an API key, so check which version you are targeting.

Available Data

Purple Air data via REST API
JSON-formatted response data
Freely accessible without authentication

Example Response

JSON Response 
{
  "status": "success",
  "data": {
    "result": "Data from Purple Air",
    "description": "Real Time Air Quality Monitoring",
    "timestamp": "2025-01-15T10:00:00Z"
  }
}

Field Reference

sensor_index Unique identifier for each PurpleAir sensor.
name Human-readable label given to the sensor by its owner.
pm2.5_atm PM2.5 particulate matter reading in micrograms per cubic meter, corrected for atmospheric pressure.
latitude Latitude coordinate of the sensor location.
longitude Longitude coordinate of the sensor location.
last_seen Unix timestamp of the most recent data upload from this sensor.

Implementation Example 

const url = "https://www2.purpleair.com/";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

403 Forbidden The newer PurpleAir API v1 requires an API key passed as the X-API-Key header.
✓ Register at develop.purpleair.com to obtain a free API key and include it in every request header.
Empty or null sensor readings Some sensors go offline or report null values when they malfunction or lose connectivity.
✓ Filter out entries where pm2.5_atm is null before processing; add a freshness check using the last_seen timestamp.
Rate limit exceeded Polling too frequently against the API exceeds the allowed request rate.
✓ Cache sensor data locally and poll no more than once per minute per sensor to stay within rate limits.

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 15/20
🔒 Security 15/15
🛠 Developer XP 15/20
✓ Reliability 7/15
Response Time 231ms

Fully tested on Apr 5, 2026

Technical Specifications

Auth No Auth
HTTPS REQUIRED
CORS UNKNOWN
Category Science & Math
Difficulty Beginner
Verified: 2026-04-04

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