How to Choose the Best Environment API in 2026
There are 17 Environment APIs in our directory. Of these, 8 require no authentication, making them ideal for quick prototyping. 8 are rated beginner-friendly.
Last updated: April 2026
Quick Comparison: Top 10 Environment APIs
| Name | Auth | HTTPS | CORS | Difficulty |
|---|---|---|---|---|
| BreezoMeter Pollen | API Key | ✓ | ? | Intermediate |
| Carbon Interface | API Key | ✓ | ✓ | Intermediate |
| Climatiq | API Key | ✓ | ✓ | Intermediate |
| Cloverly | API Key | ✓ | ? | Intermediate |
| CO2 Offset | No Auth | ✓ | ? | Beginner |
| Danish data service Energi | No Auth | ✓ | ? | Beginner |
| GrünstromIndex | No Auth | ✗ | ✓ | Beginner |
| IQAir | API Key | ✓ | ? | Intermediate |
| Luchtmeetnet | No Auth | ✓ | ? | Beginner |
| National Grid ESO | No Auth | ✓ | ? | Beginner |
Free Environment APIs (No Auth)
These APIs require no API key or signup. Start using them immediately.
CO2 Offset
⭐ Beginner's PickCO2 Offset API calculates and validates the carbon footprint of electricity consumption using the Sustainable Scope 2 framework.
Danish data service Energi
Danish data service Energi provides programmatic access to open energy data from energinet to society via REST API.
GrünstromIndex
⭐ Beginner's PickGrünstromIndex (Green Power Index) provides real-time and forecast data about the proportion of renewable energy in the German electricity grid.
Luchtmeetnet
⭐ Beginner's PickLuchtmeetnet API provides real-time and predicted air quality measurements from the official Dutch national air quality monitoring network (RIVM).
National Grid ESO
National Grid ESO provides programmatic access to open data from great britain’s electricity system operator via REST API.
PM2.5 Open Data Portal
⭐ Beginner's PickPM2.5 Open Data Portal provides free access to low-cost PM2.5 (fine particulate matter) sensor data from the LASS community network across Asia, particularly Taiwan.
Try It in 5 Minutes: CO2 Offset
Quick implementation example using CO2 Offset.
Using curl
curl https://corrently.io/books/susscope2-framework-fur-co2-emissionen-strombezug
JavaScript
const url = "https://co2offset.io/";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data); New to APIs? Read our Getting Started Guide →
Frequently Asked Questions
How many Environment APIs are available?
There are 17 Environment APIs in our directory as of 2026.
Are there free Environment APIs?
Yes, 8 Environment APIs require no authentication and are completely free to use.
What is the easiest Environment API to use?
CO2 Offset is one of the easiest to get started with. It is rated as beginner-level and requires no authentication.
Do I need an API key for Environment APIs?
It depends. 8 APIs need no authentication, 9 require an API key, and 0 use OAuth.