Carbon Interface API alternatives
API to calculate carbon (C02) emissions estimates for common C02 emitting activities. If it doesn't fit your project, here are the 10 best free Environment APIs to use instead in 2026, out of 29 in the directory.
For reference, Carbon Interface API: Callable from the browser (CORS) · HTTPS.
- 1
kanari API
Online · 527 msReal-time worldwide wildfire detections, water bomber tracking and open fire archive.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 2
Open-Meteo API
Online · 609 msFree weather API for non-commercial use.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 3

Sähkön hinta nyt API
Online · 1106 msFinnish and Nordic day-ahead electricity spot prices (15-minute), cheapest hours.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 4
WattFigure API
Online · 712 msUS electricity rates by state, with appliance and EV charging running costs.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 5
GridHub API
Online · 767 msLive wholesale electricity prices and demand across 25 grid zones.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 6
GridVigil API
Online · 1588 msPressure scores, demand, generation mix and alerts for the 10 major U.S. power grids.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 7
SustainMetrics API
Online · 697 ms18,000+ GHG emission factors from DEFRA, EPA, ADEME, Ember.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 8

Climatiq API
Online · 1435 msCalculate the environmental footprint created by a broad range of emission-generating activities.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 9
Danish data service Energi API
Online · 867 msOpen energy data from Energinet to society.
- No API key needed
- HTTPS
No authHTTPSCORS ? - 10

sensor.community API
Online · 694 msCommunity air quality sensor network data worldwide.
- Callable from the browser (CORS)
- HTTPS
User-AgentHTTPSCORS
Carbon Interface API vs alternatives
| API | API key | HTTPS | CORS | Uptime | Response | Rating |
|---|---|---|---|---|---|---|
| Required | Yes | Yes | Up | 873 ms | Not rated | |
| No | Yes | Yes | Up | 527 ms | Not rated | |
| No | Yes | Yes | Up | 609 ms | Not rated | |
| No | Yes | Yes | Up | 1106 ms | Not rated | |
| WattFigure | No | Yes | Yes | Up | 712 ms | Not rated |
| Required | Yes | Yes | Up | 767 ms | Not rated | |
| No | Yes | Yes | Up | 1588 ms | Not rated | |
| Required | Yes | Yes | Up | 697 ms | Not rated | |
| Required | Yes | Yes | Up | 1435 ms | Not rated |
See also: best Environment APIs · all Environment APIs
Carbon Interface API alternatives FAQ
What is the best free alternative to the Carbon Interface API in 2026?
The top-ranked free alternatives to the Carbon Interface API are kanari API, Open-Meteo API and Sähkön hinta nyt API, all in the Environment category. Rankings combine access (API key, HTTPS, CORS), daily uptime checks and developer ratings.
Is there a Carbon Interface API alternative that doesn't need an API key?
Yes: kanari API, Open-Meteo API and Sähkön hinta nyt API work without an API key, unlike the Carbon Interface API, which uses apiKey authentication.
How many Environment APIs are similar to the Carbon Interface API?
The directory lists 29 other free Environment APIs. This page compares the top ones side by side.