UK Carbon Intensity API

Base URL

https://api.carbonintensity.org.uk

Authentication

No API key required.

Rate limit

No published hard limit; data updates every half hour so caching is straightforward.

Pricing

Free under the Open Government Licence.

CORS

Enabled — callable directly from browser JavaScript

Official docs

Read the docs

Every request below was executed against the live API on 2026-08-19, and the response shown is the real body it returned — not an illustration.

curl 'https://api.carbonintensity.org.uk/intensity'

const res = await fetch("https://api.carbonintensity.org.uk/intensity");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);

import requests

res = requests.get("https://api.carbonintensity.org.uk/intensity", timeout=20)
res.raise_for_status()
print(res.json())

{
  "data": [
    {
      "from": "2026-08-19T19:30Z",
      "to": "2026-08-19T20:00Z",
      "intensity": {
        "forecast": 203,
        "actual": 196,
        "index": "high"
      }
    }
  ]
}

data[].from / tostring

Start and end of the half-hour settlement period, in UTC.

data[].intensity.forecastinteger

Forecast gCO2 per kWh.

data[].intensity.actualinteger

Measured value, null for future periods.

data[].intensity.indexstring

Band: very low, low, moderate, high or very high.

data[].generationmixarray

Percentage share by fuel on generation endpoints.

• Schedule compute or batch jobs for the lowest-carbon half hours
• Time EV charging or heat pump operation to clean grid periods
• Display live grid carbon intensity in a dashboard or smart home app
• Report the carbon impact of energy use with real regional data